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PART THREE: Trails, Greenway, and Outdoor Recreation Terms

Compiled and edited by Jim Schmid

Many of the glossary terms and definitions provided here were compiled for and published in Trails Primer: A Glossary of Trails, Greenway, and Outdoor Recreation Terms and Acronyms, 2001, Jim Schmid, editor, south Carollina Department of Parks, Recreation and Tourism, Columbia, SC.

The terms are listed in alphabetical order, so definitions of interest can be found quickly.

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Rabies: An infectious disease transmitted by the bite of an infected mammal. Symptoms appear anywhere from three weeks to a year after being bit and include headache and fever, cough and sore throat, loss of appetite and fatigue, abdominal pain, nausea, vomiting, and diarrhea. Once symptoms appear, it is too late for treatment. If bitten by a rabid mammal get to a doctor immediately.

Radiant Heat Loss: Is when heat radiates out from your body into your clothes. Vapor barriers reflect the heat back to your body.

Radius: An arc or curve that connects two straight trail segments in order to provide smooth horizontal and vertical alignment.

Rail Corridor: The path of a railroad right-of-way, including the tracks and a specified tract of land on either side of the tracks (generally one hundred feet wide).

Rail-Trail (Rail-to-Trail): A multi-purpose, public path or trail (paved or natural) created along an inactive railroad corridor.

Rail-with-Trail: Any shared-use path that is located on or directly adjacent to an active railroad or fixed route transit corridor.

Railbank(ing): Retaining a rail corridor for future railroad uses after service has been discontinued. The National Trails System Act, Sec. 8d, provides for interim public use of the corridor, allowing the establishment of recreational trails.

Railing: Horizontal or diagonal structural member which is attached to vertical posts for the purpose of delineating trails, protecting vegetation, providing safety barriers for trail users at overlooks, and assisting users when crossing bridges or using steps.

Rain: Water falling to earth in drops that have been condensed from moisture in the atmosphere.

Rake: A long-handled implement with a row of projecting teeth at its head. To smooth, scrape, or loosen with a rake or similar implement.

Rake, Fire: A tool with triangular tines used to cut duff and debris from firebreaks or trail corridors.

Rake, Leaf or Lawn: A tool with long tines in a fan shape. Used for clearing trail tread of leaves, needles, and other light ground litter.

Rake, Steel: A tool with short steel tines. Used to spread soil and gravel.

Rake and Ride: Used by mountain bikers to describe trails that were not constructed. Volunteers rake the leaves out of the way and folks start riding.

Rake Down: Trail construction where all spoils are distributed below or to the side of the trail vs. "full clean" where all spoils must be removed.

Ramp: A sloped transition between two elevation levels.

Range: A north-south tier of townships or sections in a US public land survey. A range of townships is described by its relationship to the principle meridian numbered east and west. An open region over which animals (as livestock) may roam and feed.

Range Improvement: A structure, excavation, treatment or development to rehabilitate, protect, or improve range conditions on public lands.

Rapid(s): An area of broken, fast flowing water in a stream, where the slope of the bed increases (but without a prominent break of slope which might result in a waterfall), or where a gently dipping bar of harder rock outcrops.

Rappel (Roping Down): Self-belaying down a length of rope to get down from a steep climb.

Rare: Plant or animal species that are uncommon in a specific area. All endangered, threatened, and sensitive species can be considered rare, but the converse is not true.

Ravine: Deep, narrow gouge in the earth's surface, usually eroded by the flow of water.

Re-supply: A termed used by distance hikers to describe detours into towns to pick up supplies, often in the form of food-laden re-supply packages that had been packaged and mailed earlier.

Reach: A section of stream between two defined points.

Read(ing): To study the terrain and obstacles to determine a course or possible locations for a trail through the area.

Real Property: Real estate; land and anything growing on it or attached to it, such as trees, fences, and buildings.

Rebar: Steel-reinforcing rod that comes in a variety of diameters, useful for manufacturing pins or other trail anchors.

Reconnaissance (Recon): Scouting out alternative trail locations prior to the final trail route location being selected.

Reconstruct (Reconstruction, Renovate): To replace or rebuild trail or trail structure (switchback, waterbar, bridge, etc.) that is no longer safe to use or in poor condition. Also can include all work to bring an existing trail up to its classification standard, including necessary relocation of minor portions of the trail.

Record of Decision (ROD): Also called a decision memo. The portion of a Final Environmental Impact Statement that identifies the proposed action, signed by the appropriate deciding officer. (NEPA process.)

Recreation: The refreshment of body and mind through forms of play, amusement, or relaxation; usually considered any type of conscious enjoyment that occurs during leisure time.

Recreation, Developed: Outdoor recreation requiring significant capital investment in facilities to handle a concentration of visitors on a relatively small area. Examples are ski areas, resorts, trailheads, and campgrounds.

Recreation, Dispersed: Outdoor recreation activities that occur outside of developed recreation facilities in which visitors are diffused over relatively large areas away from maintained roads. Also referred to as backcountry recreation. Where facilities or developments are provided, they are more for access and protection of the environment than for the comfort or convenience of the people.

Recreation, Passive Outdoor: Recreational uses conducted almost wholly outdoors that generally do not require a developed site, including hiking, horseback riding, mountain biking, and birdwatching.

Recreation Management Area(s), Extensive (ERMA): BLM administrative units where recreation management is only one of several management objectives and where limited commitment of resources is required to provide extensive and unstructured types of recreation activities. These areas consist of the remainder of land areas not included in the Special Recreation Management Areas (SRMA).

Recreation Management Area(s), Special (SRMA): BLM administrative units established to direct recreation program priorities, including the allocation of funding and personnel, to those public lands where a commitment has been made to provide specific recreation activities and experience opportunities on a sustained yield basis.

Recreation Opportunity Spectrum (ROS): A means of classifying and managing recreational opportunities based on physical, social, and managerial settings. Each of the following six ROS classes is defined in terms of its combination of activity, setting, and experience: Primitive, Semi-Primitive Non-Motorized, Semi-Primitive Motorized, Road Natural, Rural, and Urban.

Recreation Site, Developed: A site developed primarily to accommodate specific intensive use activities or groupings of activities such as camping, picnicking, boating, swimming, winter sports, etc. These sites include permanent facilities which require continuing management commitment and regular maintenance, such as roads, trails, toilets, and other facilities needed to accommodate recreation use over the long term.

Recreation Site, Semi-Developed: A site partially developed to accommodate specific intensive uses such as camping, trail access, etc. These sites may include some permanent facilities such as a parking area and/or toilet. However, regular maintenance may not occur.

Recreational Corridors: Purchased/protected primarily for recreation, although these corridors contain at least a minimal natural buffer affording some ecological and/or habitat benefits.

Recreational Opportunities: The combination of recreation settings, activities, and experience provided by the area.

Recreational Trails Program (RTP): Federal program first established in 1991, RTP returns a portion of federal gasoline taxes, generated by non-highway recreation, to the states, which in turn provide grants for trail-related purposes to private organizations, state and federal agencies, and municipalities (www.fhwa.dot.gov/environment/rectrails).

Recreational Use Statue (RUS): State law (in all 50 states) designed to limit the liability of public organizations, easement donors, landowners, and others who open their lands for public recreation use without charge.

Reforestation: The natural or artificial regeneration of an area to protect watersheds, prevent soil erosion, improve wildlife habitat and other natural resources, produce timber and other wood products, and restore function to a particular type ecosystem.

Regeneration, Natural: The revegetation of a site by natural means, whether from seedlings originating by natural seeding, or from sprouts and other plants which reproduce vegetatively. Natural regeneration may or may not be preceded by site preparation.

Register, Trail: Along long-distance trails you may find "trail registers" at overnight stops or trailheads that allow users the chance to make comments to those behind them, and read comments from those ahead. Registers can be an important safety measure to pinpoint the location of trail users.

Registration, Trail: A survey form filled out and left at a trailhead drop box or office that allows managers to obtain use information. Or a required permit to use a trail.

Rehabilitation (Rehab, Naturalize, Reclaim, Reclamation, Restoration, Restore, Revegetation): Process of restoring a denuded and/or eroded area close to its original condition.

Relief: Elevations or depressions of the land.

Relocation (Relo, Realignment, Reroute): To alter the path of an existing trail to better follow land contours, avoid drainage sites, bypass environmentally sensitive areas, improve views, or for other landowner or management reasons.

Remove: To move from a position occupied; to take away.

Request for Proposals (RFP): Allows a number of consultants to bid on a project by outlining their plans and associated costs. A detailed RFP will help weed out unqualified consultants.

Research: Systematic inquiry into a subject in order to discover new information or revise facts and theories. Research follows a scientific method and must be repeatable.

Reserve(s): Large protected areas that serve as primary sites for the conservation of biological diversity, natural resources, and in some cases for important archaeological and historic sites.

Resource Advisory Council (RAC): A group established pursuant to 43 CFR 1780 and other authorities to advise the Bureau of Land Management on resource management issues.

Rest Area: A level portion of a trail that is wide enough to provide wheelchair users and others a place to rest and gain relief from the prevailing grade and cross slope demands of a path.

Rest Area Interval: The distance between rest areas.

Rest Step: An uphill hiking technique where with each step, the rearmost leg is locked completely straight momentarily shifting weight from leg muscles to leg bones giving muscles a very short moment of complete rest.

Restrictions, Road or Trail: Limitations placed on the use of a road or trail. Sample codes: S-seasonal closure, Y-closed yearlong to motorized vehicles, R-restriction on types of traffic allowed on road or trail, L-limitations on vehicle dimensions, weight or speed, N-no restrictions applied, B-no bicycles, E-no equestrians, M-no motorized vehicle, P-permit required for use.

Restroom (Comfort Station, Pit Privy, Chum Privy, Vault Toilet, Composting Toilet, Chemical Toilet, Port-a-John, Latrine, Bathhouse): Facility for human waste disposal that may or may not meet public health standards.

Reversionary Interest (Reversion): The right of a property owner to the future enjoyment of property presently in the possession or occupancy of another. For example, a railroad company could acquire a right-of-way easement that states upon cessation of use as a rail line that the property would revert to the original owner or heirs.

Revetment: A facing of stone, bags, blocks, pavement, etc. used to protect a bank against erosion.

Rhizome: A below ground stem capable of growing a new plant.

Rhyolite: A fine-grained extrusive volcanic rock, similar to granite in composition and usually exhibiting flow lines.

Ridge: A hill that is proportionally longer than it is wide, generally with steeply sloping sides.

Ridgeline: A line connecting the highest points along a ridge and separating drainage basins or small-scale drainage systems from one another.

Ridgerunner: A person paid to travel and oversee a specific section of trail.

Riffle: A reach of stream that is characterized by shallow, fast-moving water broken by the presence of rocks and boulders.

Rift: A shallow or rocky place in a stream, forming either a ford or a rapid.

Rigging, Cable: Cable works and hoists used to lift and move large, heavy rocks or logs.

Right-of-First Refusal: A property interest in which the holder of the right has first option to purchase the property at the price of a bona fide offer made to the property owner by a third party. If not exercised within a set time period after the offer is made, it expires, and the owner is free to sell to the offeror.

Right-of-Way: A linear corridor of land held in fee simple title, or as an easement over another's land, for use as a public utility (highway, road, railroad, trail, utilities, etc.) for a public purpose. Usually includes a designated amount of land on either side that serves as a buffer for adjacent land uses.

Right of Way: The right of one trail user or vehicle to proceed in a lawful manner in preference to another trail user or vehicle.

Rill: A steep-sided small channel resulting from accelerated erosion; the most common form of erosion.

Rimrock: A top stratum of resistant rock of a plateau that outcrops to form a vertical face.

Riparian (Riparian Zone, Habitat Zone): A habitat that is strongly influenced by water and that occurs adjacent to streams, shorelines, wetlands, or other water bodies, dominated by high soil moisture content and influenced by adjacent upland vegetation.

Riparian Vegetation: Plant species growing adjacent to a wetland area, including a perennial or intermittent stream, lake, river, pond, spring, marsh, bog, meadow, etc.

Ripple: A specific undulated bed form found in sand bed streams. Undulations or waves on the surface of flowing water.

Riprap (Rip Rap): Rough, large stones or rocks placed randomly on a bank to provide support and prevent erosion; also the stone so used.

Risk: Relationship of the trail user to the danger involved of traveling through an uncontrolled environment.

Risk: Level of legal exposure incurred by land manager or owner of property for providing access to trail users.

Risk, Assumption of: The legal concept that you assumed and perceived an activity was potentially dangerous and you willingly assumed those risks and participated anyway.

Risk, Perception of: Something that happens more on site, perceiving a big drop off on a trail as being dangerous and therefore not getting too close to the edge.

Risk Management: An element of safety management that evaluates the effects of potential hazards on safety by considering acceptance, control, or elimination of such hazards with respect to expenditure of resources.

River: Large natural streams that continuously or periodically contain moving water, or which form a connection between two bodies of water.

Riverine: Relating to, formed by, or resembling a river including tributaries, streams, brooks, etc.

Road: A vehicle route that has been improved and maintained by mechanical means to ensure relatively regular and continuous use. A "way" maintained solely by the passage of vehicles does not constitute a road.

Road, Designated: Specific roads identified by the land management agency where some type of use (motorized or nonmotorized) is appropriate and allowed either seasonally or yearlong and which have been inventoried and mapped and are appropriately signed on the ground.

Road Base: A mixture of sand, clay, and gavel commonly used underneath asphalt on paved roads and trails. For trails, this material can be compacted into a fairly hard surface, yet it remains soft enough to be comfortable for trail users.

Road-crossing: Intersection of trail and road traffic. Can be the most dangerous section of a trail since they are sometimes located on ridge tops, blind hills, or hairpin turns.

Road-to-Trail Conversion: Involves narrowing an old logging road to provide a meandering trail with a solid trail tread for users.

Rock: Soil particles greater than 3 inches in diameter.

Rock, Corral: Rock placed to narrow trail corridor to direct traffic.

Rock, Igneous: Rock produced through the cooling of melted mineral matter. When the cooling process is slow, the rock contains fair-sized crystals of the individual minerals, as in granite.

Rock, Metamorphic: A rock that has been greatly altered from its previous condition through the combined action of heat and pressure. For example, marble is a metamorphic rock produced from limestone, gneiss is one produced from granite, and slate is produced from shale.

Rock, Sedimentary: A rock composed of particles deposited from suspension in water. Chief groups of sedimentary rocks are: conglomerates (from gravels); sandstones (from sand); shales (from clay); and limestones (from soft masses of calcium carbonate).

Rock Art (Petroglyph or Pictograph): An archaic to modern cultural site type consisting of incised (petroglyph) or painted (pictograph) figures such as people, animals, plants, or abstracts on a rock surface.

Rock Bar (Pry Bar): A four-foot bar of steel weighing 16 to 18 pounds with a beveled end used to move rocks.

Rock Garden: Constructed or natural rock feature that is challenging to ride or drive over.

Rock Scramble: Extremely steep trail or section that requires climbing rather than hiking.

Rod Sounding: Driving a steel rod or pipe into the ground to determine the location of firm soil or rock.

Roller-coaster: Section of trail with constant ups and downs.

Root: The part of a plant/tree, usually underground, that anchors the plant/tree. Can be a hazard to trail users when they protrude through the tread surface.

Root Ball (Rootwad): Earth and soil that is lifted up when a tree and its roots fall over.

Rope: A large stout cord of strands of fibers or wire twisted or braided together.

• Working End: The end of the rope being used at the time to tie a knot.
• Standing Part: The part of the rope not being used at the moment.
• Bight: A curve or bend in the rope. This is usually a loop through which the working end is passed.

Route: A traveled way, a means of access, a line of travel, an established or selected course of travel.

Rubble: Rough, irregular fragments of broken rock or concrete.

Rumble Strip (Milled Shoulder Rumble Strip): The intention of highway shoulder rumble strips (divots cut into pavement) is to alert inattentive drivers leaving the road surface in time for them to take corrective action.

Run: A reach of stream characterized by fast-flowing, low turbulence water.

Running Joint: A vertical joint or seam, which is continuous through two or more courses in a wall. Running joints weaken a wall and should be avoided.

Runoff: Water (not absorbed by the soil) that flows over the land surface and ultimately reaches streams.

Runout (Outrun): A section of trail, usually at or near the base of a descent, that provides adequate length and grade reduction in order for the user to safely slow, stop, or negotiate turns, intersections, or structures. Outruns are usually associated with ski touring.

Rural: Usually refers to areas with population less than 5,000.

Rural Area: Outside the limits of an incorporated or unincorporated city, town, village, or any other designated residential or commercial area such as subdivision, a business or shopping center, or community development.

Rut(s) (Entrenchment): Sunken tracks or grooves in the tread surface cut in the direction of travel by the passage of trail users or water.

Saddle: Ridge between two peaks.

Saddle Notch: A half-circle notch cut in the bottom of a log to fit over a log in the course below.

Safety Harness: A body belt or strap, usually made of nylon, for use while working near steep drop-offs. Must be of approved construction and design, and in good repair, and attached to a secure anchor point with carabiners and approved climbing rope.

Salt Marsh: An area of low lying, wet ground containing a high proportion of salt or alkali; generally in arid regions.

Salvage: Removal of trees that are dead, dying, or in imminent danger of being killed by injurious agents.

Sand: Soil particles ranging from 0.5 to 2.0 mm in diameter; individual particles are visible to the unaided human eye. Usually sand grains consist chiefly of quartz, but they may be of any mineral composition.

Sapwood: Wood just under the bark of a tree. It is only a few years old. This wood is usually a light color and not as strong or dense as the heartwood.

Savannah: A flat, almost treeless grassland.

Saw: Cutting tool that comes in a variety of styles used for cutting limbs, branches, trees, or lumber.

Scale: The proportionate size relationship between an object and the surroundings in which the object is placed. The relationship of the length between two points as shown on a map and the distance between the same two points on the Earth.

Scenery: The aggregate of features that give character to a landscape.

Scenic Area: An area whose landscape character exhibits a high degree of variety and harmony among the basic elements which results in a pleasant landscape to view.

Scenic Quality: The degree of harmony, contrast, and variety within a landscape.

Scenic Quality Evaluation Key Factors: The seven factors (land form, vegetation, water, color, adjacent scenery, scarcity, and cultural modifications) used to evaluate the scenic quality of a landscape.

Scenic View (Vista): A long-distance view that is pleasant and interesting.

Scenic Viewpoint: A designated area developed at a key location to afford trail users an opportunity to view significant landforms, landscape features, wildlife habitat, and activities.

Schrader Valve: An inner tube valve identical to those found on car tires. A tiny plunger in the center of its opening must be depressed for air to enter or exit.

Scoping: The NEPA process of identifying the range of considerations, issues, management concerns, preliminary alternatives, and other components of an environmental impact statement or land-use planning document. It involves internal agency and external/public involvement.

Scour (Scouring): Soil erosion through the force of moving water.

Screamer: A long fall.

Scree (Scree Slope): Gravel-size loose rock debris, especially on a steep slope or at the base of a cliff, formed as a result of disintegration largely by weathering.

Screening: Full or partial concealment of unsightly views to render them unnoticeable from the trail, by means of natural objects, plantings, fences, or other appropriate means.

Sea Level: The ocean surface; the mean level between high and low tides. Sea level is used as a reference point in determining land elevation.

Section: Nominally one mile by one mile area of land bounded by section lines running east-west and north-south.

Section 106 Consultation: Discussion between a Federal agency official and the Advisory Council on Historic Preservation, State Historic Preservation Officer, and other interested parties concerning historic properties that could be affected by a specific undertaking.

Section 4(f) of the US DOT Act: Section 4(f) resources consist of publicly owned parks, recreation areas, wildlife refuges, and public and private historic sites. Section 4(f) land cannot be used for US DOT-funded projects unless it is determined that no feasible and prudent alternative exists.

Section 8(d): Common reference to U.S.C. 1247(d), the section of the National Trails System Act which provides for interim trail use when a surplus railroad line is placed in the federal railbank.

Section-hiker: A hiker who is hiking an entire trail over a period of years.

Sediment: Soil particles that have been transported away from their natural location by wind or water action and re-deposited in a different area down-slope or down-stream.

Sediment Basin (Catch Basin): A natural or constructed bowl or basin to catch or slow water run-off to allow the sediment to settle out of suspension.

Sediment Deposition: The accumulation of soil particles on the trail tread and banks.

Sediment Yield: The volume or weight of sediment transported from a site.

Sedimentation: Deposition of soil particles or other material carried in water; usually the result of a reduction in water velocity below the point at which the material remains in suspension.

Seen Area: That portion of the landscape which is visible from roads, trails, rivers, campgrounds, communities, or other key observation positions.

Segment (Passage): A portion of a trail. Changes in geographic features, jurisdiction and/or political boundaries often distinguish segments (passages).

Self-Arrest: Ice-axe technique used to stop yourself from sliding off a icy mountainside. You use your body weight to plunge the serrated blade of the axe into the icy mountainside; ideally you find yourself halted midslope.

Semiarid: Moderately dry; region or climate where moisture is normally greater than under arid conditions but still definitely limits the production of vegetation.

Serac: A large pointed mass of ice in a glacier isolated by intersecting crevasses.

Setting Bed: A layer of aggregate (either crushed stone or crushed gravel), mason's sand, or mortar placed on solid rock, or a compacted subgrade of existing ground or fill as a base for a row of stone or block. Depending on the setting bed, material, and subsurface conditions, the setting bed may be from 4 to 12 inches deep.

Shaft: An opening made at the surface and extending downward into the earth vertically.

Shank: A metal or nylon plate installed in the instep of a shoe or boot to provide support.

Shared Use: A process where land managers and trail user groups work together to identify common goals and share in the process to achieve them. It means sharing of knowledge, tools, trailheads, grant funds, labor, and other resources in an area. In some instances it means sharing the same trail, but doesn't always require multiple-use trails.

Shear: Force parallel to a surface as opposed to directly on the surface. An example of shear would be the tractive force that removes particles from a trail as flow moves over the surface of the slope.

Sheath: Protective covering made of leather or plastic used to cover sharp blades of tools while in storage or when the tools are transported.

Sheetwash: The widespread removal of surface debris by the steady and continuous flow of water on low gradient slopes. Generally at slow speeds and over long periods.

Shelter (Adirondack, Lean-To, Stone, Log): Open front structure that includes a sleeping platform and roof; popular as an overnight facility on long-distance trails, especially in the East.

Sherpa(s): A member of the Himalayan people living in Nepal and Tibet who are famous for their skill as mountaineers. In modern times Sherpas have achieved world renown as expert guides on Himalayan mountaineering expeditions. To carry another's gear, as in, "I Sherpaed both of our packs the entire morning."

Shim(s) (Wedge): A short, thin wedge of wood or metal used to fill a space. Used to bring a ledger, stringer, or tread to level. Also used as a verb: to shim.

Shore: That part of the land in immediate contact with a body of water including the area between high and low water lines.

Shoreline: The line of contact between a body of water and the land.

Shoulder: The side or edge of the trail; the side or edge of a rock. The paved portion of a highway, which is contiguous to the travel lanes, allowing motor vehicle use in emergencies. They can also be for specialized use by pedestrians and bicyclists.

Shovel: A tool with either a square-edged blade for scooping moving loose material or pointed blade for digging, with either a wooden or fiberglass handle that can vary from three feet to five feet long.

Shrink-Swell Potential: The susceptibility of soil to change in volume due to a loss or gain in moisture content. A shrink-swell potential is typically associated with soils that have a high percentage of clay.

Shrub: A woody plant that usually remains low and produces shoots or trunks from the base; it is not usually tree-like or single stemmed.

Shrub Steppe: Non forested regions dominated by shrubs and grasses.

Shuttle: Leaving a vehicle at both ends of a point-to-point trip or pre-arranging a shuttle to pick you up at the end of the trip or to drop you off at the beginning.

Shy Distance: The distance between the trails edge and any fixed object capable of injuring someone using the trail.

Sidehilling: Process of excavating or cutting a trail tread across the slope.

Sideslope: The natural slope of the ground measured at right angles to the centerline of the trail, or the adjacent slope, which is created after excavating a sloping ground surface for a trailway, often termed a cut-and-fill-slope, left and right of the trail tread.

Sidewalk: A paved strip (typically concrete four feet in width) which runs parallel to vehicular traffic and is separated from the road surface by at least a curb and gutter. Sidewalks are common in urban areas and in some suburban residential areas.

Sight Line (Sight Distance): The visible and unobstructed forward and rear view seen by a trail user from a given point along the trail.

Sign (Signage): A board, post, or placard that displays written, symbolic, tactile, or pictorial information about the trail or surrounding area. Signage increases safety and comfort on trails. There are five basic types of signs: Cautionary, Directional, Interpretive, Objective, and Regulatory.

Sign, Cautionary: Warns of upcoming roadway crossings, steep grades, blind curves, and other potential trail hazards.

Sign, Directional: Gives street names, trail names, direction arrows, mileage to points of interest, and other navigational information.

Sign, Interpretive: Offers educational information that describes and explains a natural or cultural point of interest on or along the trail.

Sign, Objective: Provides information about the actual trail conditions, including grade, cross slope, surface, clear trail width, and obstacle height. This allows users to make more informed decisions about which trails best meet their trail needs and abilities.

Sign, Regulatory: Tells the "rules of the trail" by prohibiting certain uses or controlling direction of travel.

Significant: As used in NEPA, requires consideration of both context and intensity. Context means that the significance of an action must be analyzed in several contexts such as society as a whole, and the affected region, interests, and locality. Intensity refers to the severity of impacts.

Sill (Sleeper): A crosswise member (stone or timber) that supports the stringers, beams, or trusses of a bridge or boardwalk from contacting the ground. A horizontal log or timber laid in a shallow trench to support a plank or log.

Silt: Noncohesive soil whose individual mineral particles are not visible to the unaided human eye (0.002 to 0.05 mm). Silt will crumble when rolled into a ball.

bTemporary sediment barrier consisting of filter fabric, sometimes backed with wire mesh, attached to supporting posts and partially buried.

Siltation: The deposition or accumulation of fine soil particles.

Silting-in (Sand or Soil Puddle): The filling in of a drainage structure or low segment of the trail tread by sediment settling out due to improper design or construction or because of infrequent maintenance.

Single-Jack Hammer: A short handled hammer with a 3- to 4-pound head. Can be used alone to drive timber spikes, or with a star drill to punch holes in rock.

Sinkhole: A natural occurrence when the limestone crust of the earth collapses and creates a crater. Old sinkholes are often filled with water and resemble ponds.

Sinks: A term given to areas where underground rivers emerge at the ground surface. Areas surrounding sinks are generally lush with vegetation.

Site: A parcel of land bounded by a property line or a designated portion of public right of way.

Skew Angle: Less than at a right angle to a trail. Usually an oblique angle of 45 degrees or less.

Skiing, Cross-country, (Nordic): In simplest terms &endash; skiing across the countryside.

Skirt: To construct a trail around a mountain, often at an even grade, instead of climbing over the mountain.

Skyline: Rigging system with a highline by which a load is moved via a pulley, pulled by a separate rope.

Slab: A verb, describing the way that a sidehill trail maintains a more-or-less constant elevation rather than following the ups and downs of the ridge. Example: "The trail slabs to the north for 3 miles."

Slackline: Rigging system with a highline, which is lowered to pick up a load, then tightened to move the load.

Slacklining: Balancing activity invented by climbers in Yosemite National Park. User balances, walks, does tricks on a slackline (tubular nylon webbing) anchored between two trees providing a bouncy, physically challenging, mentally intense, and socially stimulating sport.

Slackpack (Slackpacking, Slackpacker, Barebacking, Barebacker): Hiking a section of a long distance trail without a backpack by either leaving it in a safe place or having someone shuttle it up the trail for you. This allows you to pack only a few pounds of essentials that suffice until you're met by outside support each night.

Slackwater: Floodwater with little or no velocity. It is formed when water in creeks, streams, or rivers backs up into low terrain, creating a temporary ponding condition.

Slalom: Zigzag descent on skis or mountain bike.

Slash: The branches, bark, tops, cull logs, and broken or uprooted trees left on the ground after a windfall/Blowdown or through logging or trail construction.

Sledgehammer: A long handled heavy hammer with a 6- to 8-pound head, usually held with both hands.

Slide: Material that has slid onto the trail tread from the backslope&emdash;possibly in quantities sufficient to block the trail.

Slip: The downslope movement of a mass of soil under wet or saturated conditions; a micro-landslide that produces microrelief in soils.

Slope: Rising or falling natural (or created) incline of the land, as shown on contour maps. Generally refers to the hillside (land) and not the trail, as trail "slope" is called the grade.

Slope, Cross: The slope or gradient of the undisturbed hillside; the amount or grade of the pre-existing sloped that is perpendicular to the direction of the trail.

Slope, Cut: The exposed ground surface resulting from the excavation of material on the natural terrain.

Slope, Fill: The exposed ground surface resulting from the placement of excavated material on the natural terrain.

Slope, Running: The average slope of a contiguous section that is in the same direction as the trail; measured by averaging the values of slop measurements taken periodically at different points along the trail.

Slope, Running Cross: The average cross slope of a contiguous section of a trail; measured by averaging the values of cross slope measurements taken periodically at different points along a given section of trail.

Slope, Percent: Number of feet rise (vertical) divided by feet of run (horizontal) times 100 to get percent slope; example: 15-feet of rise over 100-feet of run is a 15% slope.

Slope Measurements: Measurements taken on the ground or parallel with the slope of the ground. Slope measurements provide a true indication of the quantities of materials needed for construction. Maps and construction drawings for roads and utility lines are measured horizontally. Measurements taken electronically are also measured horizontally. Slope measurements can sometimes be as much as 10% greater than horizontal measurements.

Slope Stability: The resistance of a natural or artificial slope or other inclined surface to failure by mass movement.

Slough (pronounced "Sloo"): Ingress, egress, or backflow from a creek or river. Usually areas full of soft, deep mud.

Slough (pronounced "Sluff"): Material removed from the backslope by erosion or other means that has been deposited on the trail tread. Silt and debris collecting on the uphill (inside) edge of the trail tread. Slough may raise the height of the tread relative to the original level and result in water pooling on the trail or be sufficient to block the trail.

Slump (Slumping): When the trail tread material has moved downward causing a dip in the trail grade.

Smart Growth: Growth management policies and programs to support and encourage growth in existing communities, and in communities with infrastructure and other services that can accommodate that additional growth, while limiting development in agricultural and other areas.

Snag: Any standing dead, partially dead, or defective (cull) tree at least 10 inches in diameter at breast height and at least 6 feet tall.

Snowmobile: A motorized vehicle that operates on skis, pontoons, tracks, rollers, wheels, air cushion, or any other device which is designed for travel in, on, or over snow.

Sod: Plugs, squares, or strips of turf with the adhering soil.

Soil(s): The surface material (mineral materials, organic matter, water, and air) of the continents, produced by disintegration of rocks, plants, and animals and the biological action of bacteria, earthworms, and other decomposers. The four fundamental groups of soils are: gravels, sands, loams, and clays.

Soil, ABC: A soil with a complete profile, including an A, a B, and a C horizon.

Soil, AC: A soil with an incomplete profile that includes an A and a C horizon, but no B horizon. Commonly such soils are young, like those developing from alluvium or on steep, rocky slopes.

Soil, BC: A soil with a B and a C horizon but with little or no A horizon. Most BC soils have lost their A horizons by erosion.

Soil, Erodible: Soil susceptible to erosion.

Soil, Hydric: Soil that is saturated or flooded during a sufficient portion of the growing season with anaerobic conditions in the upper soil layers.

Soil, Inorganic: Mostly sandy soils containing little or no plant and animal remains.

Soil, Mineral: A soil comprised of rock fragments, sand, and smaller sized particles, and relatively free of organic matter. Mineral soil is typically buried under layers of surface organic matter. It is relatively stable and is the preferred material upon which to build a trail tread. When compacted, it also provides good support to rock walls and other trail structures.

Soil, Organic: Soil that is made up of leaves, needles, plants, roots, bark, and other organic material in various stages of decay, and has a large water/mass absorption ratio. Generally the first (outermost) layer of soil.

Soil Auger: T-shaped tool with a spiral tip for turning into soil to probe its content.

Soil Cement (Cement-Treated Base): A mixture of pulverized soil combined with measured amounts of portland cement and water and compacted to a high density. As the cementing action occurs through hydration, a hard, durable semi-rigid material is formed. It must have a seal coat to keep out moisture and a surface that will withstand wear.

Soil Compaction: A decrease in the volume of soil as a result of compression stress.

Soil Genesis: The mode of origin of the soil, with special reference to the processes responsible for the development of the true soil from the unconsolidated parent material.

Soil Map: A map showing the kinds of soil types and their boundaries in all the detail significant to soil use and management.

Soil Profile: Site-specific arrangement of soil layers from surface to bedrock.

Soil Stabilization: Measures that protect soil from the erosive forces of raindrop impact and flowing water. They include, but are not limited to, vegetative establishment, mulching, and the application of soil stabilizers to the trail tread.

Soil Stabilizer: Material, either natural or manufactured, used to hold soil in place and prevent erosion due to water, gravity, or trail users. Stabilizers include soil cement, geogrid, etc.

Sonotube(s): Hollow cardboard cylinders used for forming round concrete columns. The sonotube is removed after the concrete sets.

Spall(s): Stone chip or fragment; to break up into chips or fragments. Spalls are wedged between stones that have been placed without mortar. They have a function similar to that of shims used in wood or metal construction.

Special Management Area (SMA): SMAs include Wilderness Study Areas, Wild and Scenic Rivers, Research Natural Areas, and Areas of Critical Environmental Concern Areas.

Special Recreation Use Permit (SRUP): A permit issued under established laws and regulations to an individual, organization, or company for occupancy or use of federal lands for some special purpose such as a motorcycle race, outfitter guide, etc.

Species: A unit of classification of plants and animals consisting of the largest and most inclusive array or sexually reproducing and cross-fertilizing individuals which share a common gene pool.

Species, Invasive or Exotic: Non-native plant or animal species that invades an area and alters the natural mix of species by aggressively out-competing native species.

Species, Sensitive: Any plant or animal species for which population viability is a concern as evidenced by significant current or predicted downward trends in population numbers or density, or habitat capability that would reduce a species' existing distribution.

Species, Threatened or Endangered: Any plant or animal species that is in danger of extinction throughout all or a significant portion of its range, and has been officially listed as endangered by the Secretary of Interior or Commerce under the provisions of the Endangered Species Act. A final rule for the listing has been published in the Federal Register.

Specifications: Written provisions and requirements (standards) for the performance of work and type of materials to which trails (tread, clearing, grade) and trail structures (bridge, culvert, puncheon) are built and maintained according to type of use.

Specifications, Special Project: Specifications that detail the conditions and requirements peculiar to an individual trail project, including additions and revisions to the standard specifications.

Specifications, Standard: A book of specifications approved for general application and repetitive use.

Specifications, Supplemental: Approved conditions and revisions to the standard specifications.

Spelunking (Caving): Entering caves or caverns for the purpose of recreation or exploration.

Spike (Camp): To camp out while working on a trail.

Spillway: A constructed passage for surplus water to run over or around a reservior.

Sponsor: Organization or government agency that will sign agreements and contracts and be responsible for a trail or greenway project.

Sport Utility Vehicle (SUV): A street legal, high clearance vehicle used primarily on-highway but designed to be capable of off-highway travel.

Sprawl, Urban: Low-density land-use patterns that are automobile-dependent, energy and land consumptive, and require a very high ratio of road surface to development served. Scattered, untimely, and often unplanned, urban development that occurs in urban fringe and rural areas without provisions for facilities and services and is characterized by strip development.

Spring (Seep, Seepage): A saturated zone at or near the ground surface where voids in the rock or soil are filled with water at greater that atmospheric pressure. A seep is a small spring. Seep or spring sites are typically characterized by riparian vegetation and soil formed in the presence of water. Water may or may not be discharging from these sites, depending on the underlying geology, water source, season, or long term climatic trends.

Square Notch: A notch cut in a log to fit snugly against a square notch cut in another log, the square cut end of another log, or a plank. The portion of the notch in contact with the other log is cut as a flat, uniform plane. The ends or ends of the square notch are perpendicular to the flat plane.

Staging Area: An area where users can congregate, park, and begin or end a trip. Designed and managed for day use, whereas a trailhead usually caters to those embarking on an overnight or long-distance trip.

Stakeholder(s): Group or individual who can affect, or is affected by, the achievement of the organization's mission; examples include managers, employees, policy makers, suppliers, vendors, citizens, and community groups.

Stakes, Grade or Slope: Temporary stakes set by the trail locator to establish the elevation and cross section of the completed tread.

Stakes, Line: Temporary stakes set by the trail locator to establish the centerline of the trail.

Stand: A community of trees possessing sufficient uniformity in composition, age arrangement, and condition as to be distinguishable from trees in adjoining areas.

Standard(s): A statement and/or illustration describing a design recommendation or principle that recommends a preferred development technique for use as a rule or basis of comparison in measuring maximum or ideal requirements, quantity, quality, value, etc.

Standards, Design: The specific values selected and documented from the design criteria become the standards for a given trail or greenway project. These standards will be identified and documented by the designer. Standards will related to the physical characteristics, users, location, and environmental factors of a project.

Star Drill: A foot-long tool, weighing about a pound, used with a single-jack hammer to punch holes in rock or open a seam/crack.

State Land: Lands administered by any one of several state agencies.

Statewide Comprehensive Outdoor Recreation Plan (SCORP): Recreation management plan developed periodically (about 10 years) by each State to help Federal, State, and local agencies assess recreational use trends and the needs for future management and facilities.

Station: One hundred feet or other set measurement along the centerline of the trail or road; used in surveying and construction.

Stationary Sound Test: A test procedure, approved by the Society of Automotive Engineers (SAEJ1287 Jul98), to readily test vehicle sound levels in the field.

Statute: Law passed by Congress or a state legislature that declares, commands, or prohibits something.

Steel Rungs: Placed on rock faces or ledges to provide ladder-like access in steep terrain.

Step: Structure (stone or wood) that provides a stable vertical rise on the trail, usually in sets.

Step, Pinned: Step held in place on a ledge or a rock slab by steel pins set in holes drilled in the rock.

Steward: The person taking responsibility for the well-being of land and water resources and doing something to restore or protect that well-being.

Stewardship: Taking responsibility for the well-being of land and water resources and doing something to restore or protect that well-being. It usually involves cooperation among people with different interests and sharing of decision-making. It is generally voluntary. It is oriented towards assessment, protection, and rehabilitation of trails and greenways as well as sustainable use of renewable resources.

Stile: A ramp, step, or set of steps for hikers to pass over a fence or wall without allowing livestock to escape.

Stipend: Fixed amount of money for expenses (i.e. food, fuel, etc.) paid to volunteers by agencies or organizations in lieu of a salary.

Stob: A short straight piece of wood, such as a stake.

Stock (Recreational Stock, Pack Stock): Riding and/or pack animals (horses, mules, llamas, burros, goats, etc.) used to ride and/or carry equipment and provisions on a trail. Both commercial pack stock and individual stock are included. Commercial stock in area of trail can be cattle or sheep grazing.

Stolon: An above-ground stem capable of growing a new plant.

Stone: Rock or rock fragments put to human use.

Stone, Cap (Cap Rock): Stone or rock placed in the top or uppermost layer of a constructed structure such as a rock retaining wall.

Stone, Dry (Dry Stack): Construction technique of stacking rock or stone without mortar or other adhesive.

Stone, Key: A large stone that holds others in place. Also called an anchor.

Stone(s), Stepping: Large rocks (preferably greater than two hundred pounds) set in boggy areas or shallow stream crossings to provide passage for hikers.

Stone, Tie: A header or keystone that spans the breadth of the trail tread.

Stone Pitching: Ancient form of road/trail building similar to cobblestone.

Straw Bale: Temporary barriers made from bales of straw that are sometimes installed across a slope or around the perimeter of a construction site to intercept and detain sediment transported by runoff.

Stream: Small body of running water moving in a natural channel or bed.

Stream, Alluvial: Any stream whose banks are subject to attack, allowing soil, sand, or gravel to build up in one area while washing it away in another.

Stream, Ephemeral: A temporary or short-lived water flow only in direct response to a heavy rain. Most of the year it's a dry bed.

Stream, Intermittent: Channels that naturally carry water part of the year and are dry the other part.

Stream, Perennial: Stream channels that carry water year round.

Stream Bank: The side slopes of an active channel between which the streamflow is normally confined.

Stream Channel: A long narrow depression shaped by the concentrated flow of a stream and covered continuously or periodically by water.

Stream Crossing: A trail crossing a body of running water at grade without the use of a developed structure or bridge.

Streambed: The unvegetated portion of a channel boundary below the baseflow water level. The channel through which a natural stream of water runs or used to run, as a dry streambed.

Streamflow: The rate at which water passed through a given point, usually expressed in cubic feet per second.

Street: Any public thoroughfare (street, avenue, boulevard, or park) or space more than 20 ft wide which has been dedicated or deeded to the public for public use.

Stringer(s): The lengthwise members of a structure placed parallel with the centerline of the tread, usually resting on sills, which spans wet areas and supports the decking.

Structure: Anything constructed or erected that requires location on the ground such as a bridge, wall, steps, etc. on or near a trail.

Stub: Projecting (and hazardous) piece of a branch, root, or sapling not cut flush with the trunk or ground.

Stuff Sack: A water-repellant or waterproof bag with a drawstring, used for compact storage of gear.

Sub-base: On paved trails the sub-base lies between the sub-grade and the trail surface, and serves as a secondary, built foundation for the trail surface (concrete or asphalt). The purpose of the sub-base is to transfer and distribute the weight from the trail surface to the sub-grade. The sub-base consists of four- to six-inches of graded aggregate), which provides bearing strength and improves drainage.

Sub-grade: The native soil mass that makes up the primary foundation of the trail that supports the tread surface. Topography, soils, and drainage are the key factors comprising the sub-grade.

Subalpine: A terrestrial community that generally is found in harsher environments than the montane terrestrial community. Subalpine communities are generally colder than montane and support a unique clustering of wildlife species.

Subsoil: The soil below the surface soil in which roots normally grow. It has been carried over from early days when "soil" was conceived only as the plowed soil and that under it as the "subsoil."

Substrate: Underlying layer of loose/soft material below topsoil and overlying bedrock. The composition of a streambed, including either mineral or organic materials.

Subsurface Drainage: Rainfall that is not evapotranspirated or does not become surface runoff.

Subsurface Rights: The right to use or control land below the trail surface. Subsurface rights may be leased for water, sewer, or fuel pipelines; or electrical, telephone, or fiber-optic cables.

Suitable Material: Rock that can be accommodated in the trail structure, and soil free of duff with a recognizable granular texture.

Summit: The highest point (top) of a mountain.

Summit: A conference or meeting of leaders or advocates, usually called to shape a program of action.

Summit, False: You think you're at the top, but you're not. Keep climbing.

Super-Elevated (Superelevation, Bermed, Banked): Slope or bank of a curve or climbing turn expressed as the ratio of feet of vertical rise per foot of horizontal distance. The outside edge of a trail is raised or banked for the purpose of overcoming the force causing a vehicle (bicycle or OHV) to skid when maintaining speed in a curve.

Surface (Surfaced, Surfacing): Material on top of the trailbed or base course that provides the desired tread. It can lessen compaction of soil, provide a dry surface for users, and prevent potential erosion and abrasion. In addition to concrete and asphalt, trails can be surfaced with dirt, rock, gravel, sand, mud, snow, grass, and other substances.

Survey: The plat and the field-note record of the observations, measurements, and monuments descriptive of the work performed.

Survey, Trail (Condition Survey): A physical field assessment of the trail or proposed trail, to determine alignment, maintenance tasks, hazards, impact, etc., prior to work, or as part of ongoing trail maintenance.

Survey, Visitor: Most frequently used method of obtaining detailed information on visitor characteristics, attitudes, and preferences. Consists of two parts: 1) contacting a sample of visitors (either at trailheads or at home): and 2) obtaining visitor use information by either interviewing visitors or asking them to respond to a questionnaire.

Suspension Bridge: A bridge that has its treadway suspended from two or more cables securely anchored at the ends.

Sustainable (Sustainability): Community use of natural resources in a way that does not jeopardize the ability of future generations to live and prosper.

Sustainable Development: Development that maintains or enhances economic opportunity and community well-being while protecting and restoring the natural environment upon which people and economies depend. Sustainable development meets the needs of the present without compromising the ability of future generations to meet their own needs.

Swag (Schwag): Any corporate/branded merchandise given out for free in order to promote the company/brand. Usually little trinkets, stickers, sometimes clothing, and always cheaply mass-produced. Etymology of this term most likely stems from a middle-English use of the word "swag" often in pirate circles or other criminal circles as a euphemism for loot or plunder.

Swale: A linear low-lying natural topographic drainage feature running downhill and crossing the trail alignment in which sheet runoff would collect and form a temporary watercourse. A low-lying ground drainage structure (resembling a swale) can be constructed to enhance drainage across the trail.

Swamp: Low lying land saturated with moisture and overgrown with vegetation but not covered with water.

Swedish Safety Brush Axe (also known as a Sandvik): A machete-like tool with a protected short, replaceable blade and a 28-inch handle used to cut through springy hardwood stems.

SWECO Trail Dozer: Sutter Welding and Equipment Company builds the 450 and 480 trail dozers specifically for trail construction and maintenance. The dozers are 40 inches wide by about 11 feet long and 6 feet high. They weigh about 8,000 pounds, are powered by turbo diesel engines, and have hydraulic controls with full hydrostatic drive. The 6-way floating blade and rock rippers allow for the removal of most rock and roots from the trail bed, leaving a smooth and sustainable finished trail surface.

Switchback: A sustainable sharp turn on a hillside (usually on a slope of more than 15%) to reverse the direction of travel and to gain elevation. The landing is the turning portion of the switchback. The approaches are the trail sections upgrade and downgrade from the landing.

Switchback, Rolling Crown: A sustainable turn on a hillside engineered for drainage. The trail is routed onto a crowned deck where it makes a transition to the opposite direction. The upper approach is insloped to drain water out the back of the landing and the lower approach is outsloped.

Sylvan: Of, found, or living in the woods or forest.

System: Set of interconnected components that function as a whole and thereby achieve a behavior or performance that is different than the sum of each of the components taken separately.

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

Tableland: High flatland or plateau.

Tack: Bridles, saddles, and other equipment used on horses and pack stock.

Tackifier: Material sprayed onto a soil surface to bind soil particles and prevent erosion.

Tailings: The dump at a mineral processing plant; material remaining after metal is extracted from ore.

Tailwater (Tailrace): The area immediately downstream of a spillway.

Taking: A real estate term traditionally used to mean acquisition by eminent domain but broadened by the US Supreme Court to mean any government action that denies viable economic use of property.

Talus (Talus Slope): Large rock debris on a slope or at the base of a hill or cliff. The rocks are larger and have sharper edges than those found on scree slopes.

Tamping: Using a narrow machine compactor, a tamping bar, or the handle of a shovel, or other tool to compact earth backfill around a post, pole, or pile.

Tarn: A small mountain lake or pond created by glacial movement.

Technical: A section along a trail that is difficult to navigate; used by mountain bikers to describe challenging sections of trail.

Technical Assistance: Help (advice and knowledge; usually not financial) offered by federal and state agencies to local groups developing trails and greenways.

Technical Trail Feature (TTF): An obstacle on the trail requiring negotiation, the feature can be either built or natural, such as an elevated bridge or a rock face respectively.

Ten Percent Rule: Laying out a trail so that the overall grade is under 10% with maximum not to exceed 15%.

Ten Percent Average Guideline: Generally, an average trail grade of 10% or less is most sustainable. This does not mean that all trail grades must be kept under 10%. Many trails will have short sections steeper than 10%, and some unique situations will allow average trail grades of more than 10%.

Tent Pad(s): An area the size of a tent where soil and gravel are built up inside some cribbing (log or stone) to improve drainage.

Tent Platform(s): Wooden platform (single, double, or group tent sizes) used to minimize damage to fragile alpine or wetlands areas, or to reduce impact on heavily used, erosion-prone campsite(s).

Tent Site(s): A designated flat, dry spot where a tent may be pitched. Site may have a central fire pit and pit toilet.

Terminus: Either the beginning or end of a trail.

Test Boring: A deep, narrow hole drilled into the ground with a power auger. A record is kept of the types of soils encountered and their depth.

Test Hole(s): Dug by hand or with a backhoe, test holes are wider than test borings, allowing the soil strata on the sides of the hole to be easily seen.

Texture: The visual manifestations of the interplay of light and shadow created by the variations in the surface of an object or landscape. Refers to relative proportions of clay, silt, and sand in soil.

Texture, Soil: Relative proportions of the various size groups of individual soil grains in a mass of soil. Specifically, it refers to the proportions of clay, silt, and sand in soil.

Texturing: The act of placing natural features (rock, logs) back into a trail to help control speed or user conflict.

Three-Hour Tour: A short hike or ride that looks all too easy at the trailhead until unforeseen events makes it an all day affair.

Thru-Hiker: Someone who attempts to cover a long trail, such as the Appalachian Trail, in one continuous trek.

Tide Flats: Saltwater wetlands that are characterized by mud or sand and daily tidal fluctuations.

Tie Log: Structural member notched into the horizontal facer and wing walls used to secure the facer and wings by utilizing the mass of the backfill.

Tight and Technical: A type of trail design that allows for tight turns and slow speeds, while using natural features as technical obstacles.

Timber: Wood that has been sawn or hewn into a square or rectangular cross section that is at least 3 inches thick.

Timber Carrier (Log Carrier): A tool, with a long handle and hooks, which allows two people on each side of the carrier to transport logs or timber.

Title: Rights of ownership of property; paper that indicates ownership.

Title Search: A legal review of deeds of record in the chain of title to a piece of property analyzing all encumbrances or prior sales of the property to make sure that a piece of real estate can be sold without anyone else claiming rights to it.

Toe: The break in slope at the foot of a bank (trail or stream) where the bank meets the bed.

Toenail(ing): Joining two pieces of wood by driving nails at an angle to the surface of one piece and into the second piece.

Top Bank (Top of Bank): The break in slope between the bank and the surrounding terrain.

Topographic (Topo, USGS Topographic, Contour) Map: Maps that indicate built and natural features (buildings, roads, ravines, rivers, etc.) as well as elevation changes and land cover. United States Geological Survey maps are available from many government offices, outdoor shops, and map stores; or from digitized versions on the Internet.

Topographic: Of or having to do with topography or the physical features of a place.

Topography: The elevation and slope of the land as it exists or is proposed. It is represented on drawings by lines connecting points at the same elevation. Typically illustrated by dashed lines for existing topography and solid lines for proposed.

Torrent: A turbulent, swift-flowing stream. A heavy downpour, a deluge.

Township: The unit of survey of the public lands; normally a quadrangle approximately six miles on a side with boundaries conforming to meridians and parallels within established limits, containing thirty-six sections, some of which are designed to correct for the convergence of meridians or range lines.

Track: Mark left by something that has passed along; footprint or wheel rut. A pair of parallel metal rails on which trains run.

Track, Fitness (Jogging Track): Path or course laid out for exercise (walking, jogging, running). Usually no more than a mile and laid out in an oval.

Track Tie Memory: On rail-trails the removed railroad cross ties can leave an imprint (or memory). To remove this "memory" the ballast needs to be graded and compacted before laying a trail surface.

Trackstand: A skill where a (motorcycle or mountain bike) rider comes to a full stop without putting a foot down. On a technical trail, a trackstand lets you pause to decide what to do next, and it may save you from toppling over if you suddenly come to an unexpected halt.

Trail: A designated route on land or water with public access for recreation or transportation purposes such as walking, jogging, motorcycling, hiking, bicycling, ATVing, horseback riding, mountain biking, canoeing, kayaking, and backpacking.

Trail, Access: Any trail that connects the main trail to a town, road, or another trail or trail system.

Trail, Backcountry: A primitive trail (can be open to motorized or nonmotorized users) in an area where there are no maintained roads or permanent buildings.

Trail, Balloon: A trail that starts along a linear route and then branches out to a loop.

Trail, Blaze a: This expression was first used literally in the 18th century for the practice of marking a forest trail by making blazes, that is, marking trees with notches or chips in the bark.

Trail, Braided (Braiding): The process or name of undesirable multiple parallel paths created by users.

Trail, Connecting or Side: Name give to trails providing additional points of access to national recreation, scenic, or historic trails per the National Trails System Act.

Trail, Contour: A trail constructed or exists such that it follows a contour, with its elevation remaining constant. Constructed at full bench with outslope, grade reversals, and sustained grades.

Trail, Crowned: A trail bed built up from the surrounding area and sloped for drainage (usually by excavating trenches parallel to the trail).

Trail, Dendritic: Resemble linear trails except that they have many branches which are, for the most part, unconnected to each other, and which terminate in dead ends.

Trail, Designated: Specific trails identified by the land management agency where some type of use (motorized or nonmotorized) is appropriate and allowed either seasonally or yearlong and which have been inventoried and mapped and are appropriately signed on the ground.

Trail, Destination: A trail that connects two distinct points (A to B) rather than returning the user to the original beginning point.

Trail, Directional Use (One-way): A trail laid out in such a way as to encourage users to travel in one direction.

Trail, Doubletrack: A trail that allows for two users to travel side by side, or to pass without one user having to yield the trail. Doubletrack trails are often old forest roads.

Trail, Extended: Trails over 100 miles in length (as defined in the National Trails System Act).

Trail, Fall Line: Trail constructed on the fall line (direction water flows down a hill) which encourages water to run down the trail.

Trail, Feeder: A trail designed to connect local facilities, neighborhoods, campgrounds, etc. to a main trail.

Trail, Flat: A trail built across level terrain. The terrain is without a pronounced cross slope and has inefficient or unpredictable drainage. Techniques for flat trail include elevated tread or a system of channels to improve trail drainage.

Trail, Frontcountry: Less emphasis is put on minimizing contact with signs of the civilized world. The main objective is to provide enjoyable trail experiences within the vicinity of developed areas by utilizing the scenic and interpretative features of semi-urban, rural, and natural environments.

Trail, Greenway (Urban Trail): A trail established along a natural corridor, such as a river, stream, ridgeline, rail trail, canal, or other route for conservation, recreation, or alternative transportation purposes. Greenway Trails can connect parks, nature preserves, cultural facilities, and historic sites with business and residential areas.

Trail, Hard Surface (Paved): A trail tread surfaced with asphalt, concrete, soil cement, or other hard, stabilized material.

Trail, Hiker-Biker: An urban paved trail designed for use by pedestrians and bicyclists.

Trail, Hiking: Moderate to long distance trail with the primary function of providing long-distance walking experiences (usually two miles or more).

Trail, Interpretive (Nature Trail): Short to moderate length trail (1/2 to 1 mile) with primary function of providing an opportunity to walk or paddle and study interesting or unusual plants or natural features at user's pleasure. The ideal nature trail has a story to tell. It unifies the various features or elements along the trail into a related theme.

Trail, Linear: Trails that run generally straight (usually along a linear feature) and start and return exactly along the same route and have a beginning and an end.

Trail, Long Distance: In general a trail best characterized by length (more than 50 miles), linearity (follows a linear feature), and diversity (geographic and political).

Trail, Loop(ed): Trail or trail systems designed so that the routes are closed circuits connecting a number of points of interest, giving users the option of not traveling the same section of trail more than once on a trip.

Trail, Multiple-Use (Multi-Use, Diversified Use, Shared Use): A trail that permits more than one user group at a time (equestrian, OHVer, hiker, mountain bicyclist, etc.).

Trail, Natural Surface: A tread made from clearing and grading the native soil, and with no added surfacing materials.

Trail, Open and Flowing: A type of trail design that provides tempo and rhythm by incorporating sweeping turns, higher speeds, passing zones, and better sight lines. Primarily applies to bicycling and motorized traffic.

Trail, Out-and-Back: A one-way trail on which you travel to a destination then backtrack to the trailhead.

Trail, Pack: A trail used by recreational stock; usually extended trails used by pack stings for overnight trips.

Trail, Primary: Continuous through route that originates at a trailhead. Primarily for directing users through an area while promoting a certain type of experience.

Trail, Recreation: A trail that is designed to provide a recreational experience.

Trail, Regional: An extended or longer trail that may cross one or more land management agency jurisdictions and connects diverse trail systems.

Trail, Rolling Contour: A trail characterized by gentle grade, grade reversals, and outsloped tread.

Trail, Secondary: Short trail used to connect primary trails or branchings of primary trails. They encourage movement between two primary trails or facilitate dispersal of use through secondary branching.

Trail, Side: Dead-end trail that accesses features near the main trail.

Trail, Sidehill: Where the trail angles across the face of a slope. The tread is often cut into the slope.

Trail, Spine: A regional trail that acts as a "backbone" to a regional trail system.

Trail, Single-Track: A trail so narrow that users must generally travel in a single file.

Trail, Single-Use: One that is designed and constructed for only one intended use (i.e. hiking only).

Trail, Soft Surface: An unsurfaced natural trail or a trail surfaced with compacted earth, crusher fines, bark, or gravel.

Trail, Spur: A trail that leads from primary, secondary, or spine trails to points of user interests such as overlooks, campsites, etc.

Trail, Stacked Loop: Trail or trail systems designed with many loops "stacked" on each other, giving users the option of not traveling the same section of trail more than once on a trip.

Trail, Stock (Stock Driveway): A route/trail used by commercial stock.

Trail, Sustainable Natural Surface: A trail that supports currently planned and potential future uses with minimal impact and negligible soil loss while allowing the naturally occurring plant systems to inhabit the area, recognizing required pruning and eventual removal of certain plants over time. The sustainable trail will require little rerouting and minimal maintenance over extended periods of time.

Trail, Tight & Technical: Section along a trail that is filled with obstacles such are rocks, roots, logs, sharp turns, and steep grades, making it difficult to navigate and putting a premium on (motorcycle or mountain bike) riding skills.

Trail, Undesignated (Social, Wildcat, Way, Informal, User or Visitor Created): Any unofficial trails that develop informally from use and are not designated or maintained by an agency; often found cutting switchbacks or between adjacent trails, campsites, or other sites of interest. Undesignated trails can be dangerous, eroded, and unsustainable.

Trail, Undulating: One that follows a wavelike course, often going in and out of gullies.

Trail, Water (River Trail, Canoe Trail): A recreational waterway on lake, river, or ocean between specific points, containing access points and day use and/or camping sites for the nonmotorized boating public.

Trail Access Information: Objective information reported to trail users through signage, about the grade, cross slope, tread width, and surface of a trail.

Trail Angel(s): Name given to anyone who goes out of their way to help out a trail user by offering food, shelter, or a ride into town out of the goodness of their hearts rather than for profit or gain.

Trail Care Crew (TCC) Program: Subaru/IMBA sponsored two-person crews that travel and teach trail users and managers how to design, build, maintain, and manage trails that are environmentally sound and fun to use.

Trail Community: Includes those with an interest in, or relationship to a particular trail (long distance or system): volunteers, landowners, government agency personnel, and the officials and citizens of local communities through which the trail passes or trail system is located. For example, there is the Appalachian Trail community.

Trail Design: Designing and layout of trails requires special training, knowledge, experience, and skill. When designing trails, many different factors are taken into account including hydrology, topography, soils, flora, fauna, management objectives, user expectations and characteristics, and trail design standards. The designer will utilize data collected from area site analysis, environmental assessments, public meetings, and area trail and management plans.

Trail Magic: The special unexpected pleasures that happen and the generosity that trail users experience while on a trail trip.

Trail Management Objective (TMO): The goals and objectives pertaining to a specific trail management project (new construction, maintenance, reroute, bridge, etc.). Usually intended to provide guidance for a trail crew leader.

Trail Name: A chosen or given nickname a trail user adopts while on an extended trail trip to identify themselves when making register entries, often based on personality, lifestyle, or traveling style.

Trail Protection: Implies that where a trail is threatened by development or where the route is constantly being rerouted, specific measures are invoked to guarantee a permanent or protected status. When a trail is adequately protected, development cannot dismember it or destroy its values to trail users.

Trail Runner(s): People who find pleasure runner on trails instead of asphalt.

Trail System(s): A collection of individual trails that may or may not be connected to one another, whereby each retains its distinctiveness, and yet belongs to the system by association with a federal, state, local, or bioregional context.

Trailbed: The finished surface on which base course or surfacing may be constructed. For trails without surfacing, the trailbed is the tread.

Trailblazer: One that blazes a trail. An innovative leader or pioneer in a field.

Trailbuilder(s): Those that build trails.

Trailhead: An access point to a trail or trail system often accompanied by various public facilities, such as hitching posts for horses, a horse or OHV unloading dock or chute, parking areas, toilets, water, directional and informational signs, and a trail use register. Designed and managed for those embarking on an overnight or long-distance trip, whereas a staging area caters to trail day use.

Trailway: The portion of the trail within the limits of the excavation and embankment.

Trample (Trampling): To tread heavily so as to bruise, crush, or injure; refers to the process of vegetation being destroyed by trail users.

Tramway: A track or way for street cars or trams (open, box-shaped wagon run on tracks). The abandoned right-of-way can be used as a trail.

Transpiration: An essential physiological process in which plant tissues give off water vapor to the atmosphere.

Transportation Enhancement: Projects that include: providing bicycle and pedestrian facilities; converting abandoned railroad rights-of-way into trails; preserving historic transportation sites; acquiring scenic easements; mitigating the negative impacts of a project on a community by providing additional benefits; and other nonmotorized projects.

Transportation Equity Act for the 21st Century (TEA-21): Federal legislation authorizing highway, highway safety, transit, and other surface transportation programs from 1998 through 2003. It provides funding opportunities for pedestrian, bicycling, and public transit facilities, and emphasizes intermodalism, multimodalism, and community participation in transportation planning initiated by ISTEA.

Travelway: The trail as a whole, including the trail tread and the cleared areas on either side of the trail.

Traverse: To cross a slope horizontally going gradually up and across in lieu of the more direct up-and-over (up the fall line) approach.

Tread (Treadway): The surface portion of a trail upon which users travel excluding backslope, ditch, and shoulder. Common tread surfaces are native material, gravel, soil cement, asphalt, concrete, or shredded recycled tires.

Tread Creep: When the loose soil of the trail tread moves (sags or slides) downhill because of erosion or use. Specific causes include bushes or trees protruding into the trail from above, exposure of roots from an uphill tree, an improper bench cut, or poor trail flow.

Tread Lightly!: Educational program designed to instill outdoor ethics of responsible behavior when participating in outdoor activities (www.treadlightly.org).

Tree: Any woody plant that normally grows to a mature height greater than 20 feet and has a diameter of four inches or more at a point four feet above the ground.

Tree Line (Timber Line): The farthest limit, either in altitude on a mountain, or the farthest north in the northern hemisphere, in which trees are able to grow. Beyond this line, the environment is too harsh for trees to survive.

Trek: To hike a long way. Trekkers are long-distance hikers.

Trekking Pole(s): Telescoping hiking poles used in pairs. Each pole, when planted, reduces weight on the legs and back thereby reducing fatigue, increasing speed, and providing stability when hiking with or without a backpack.

Trench (Trenched, Trenching): Badly eroded trail in which the user travels in a ditch down the center that may be knee deep or deeper. Any long furrow or ditch cut in the ground.

Trespass: The use of private or public land without authority, resulting from an innocent, willful, or negligent act.

Trespasser: Person who uses property without the owner's implied or stated permission and not for the benefit of the property owner. Due the least duty of care and therefore pose the lowest level of liability risk.

Trestle: Mid-span support for a bridge.

Trials (Observed Trials): A slow-speed event in which the objective is to ride (trials motorcycle or trails bike) over a difficult, obstacle-filled course without putting a foot on the ground to prevent yourself from falling over. The winner is the rider who puts a foot down least often.

Triangulation: System of equating compass and maps to a known landmark.

Tributary: A river or stream feeding into a larger waterway or lake.

Tricycle: Three wheeled toy designed for small kids to be ridden only on sidewalks, and always under parental supervision.

Trio Maintenance: Three-step function of removing slough, berm, and brush. Also called fire line trail maintenance.

Triple Crown Trails: The Appalachian Trail (2,167 miles long), the Pacific Crest Trail (2,650 miles), and the Continental Divide Trail (approximately 3100 miles) are known as the "Triple Crown" of long-distance trails.

True North: The direction toward the geographic North Pole. Most maps are oriented to True North.

Tumpline: A strap slung over the forehead, to anchor a backpack.

Tunnel: Horizontal or nearly horizontal underground or underwater passageway. Tunnels are used for mining, as passageways for trains and motor vehicles, for diverting rivers around dam sites, for housing underground installations such as power plants, and for conducting water.

Turbidity: A measure of the content of suspended matter that interferes with the passage of light through the water or in which visual depth is restricted. Suspended sediments are only one component of turbidity.

Turn: Where a trail or river changes course or direction.

Turn, Climbing: A turn on a hill to reverse direction that doesn't have a constructed turning platform or landing. The upper and lower legs of a climbing turn are generally joined by a short section of trail (the apex of the turn) that lies directly in the fall line. As a result, climbing turns located on hillsides with a grade of more than 7% are erosion prone and should be replaced with well-built switchbacks.

Turn(s), Inside: On a trail traversing a hillside, concave, or naturally banked turns in which the sideslope helps direct trail users around the turn.

Turn(s), Outside: Convex or off-camber turns (usually on trails that traverse hillsides) that are more difficult to navigate, as centrifugal force pulls trail users to the outside of the turn. Turns in which the ground slopes toward the outside, making it harder to keep (wheeled) traction as speed increases.

Turn, Thru-Cut Climbing: A turn which is constructed on a sidehill of 20% or more when measured between the exterior boundaries of the turn, and which cuts through the sidehill grade as it changes the direction of the trail 120 to 180 degrees.

Turnout: A place where the trail is widened to permit trail traffic traveling in opposite directions to pass.

Turnpike (Turnpiking): A trail building technique of raising the trail bed above wet, boggy areas by placing mineral soil over fabric between parallel side logs or rocks (along edge of tread). The tread must be "crowned" and ditches dug alongside the logs or rocks to provide drainage.

Turnpike: Slang term for overused trail for getting trail users to more scenic backcountry. Often wide, always crowded.

Turtling: To fall backwards onto one's backpack at an angle that makes it exceedingly difficult to right oneself. Always funny when it happens to someone else.

Twist: A defect in lumber and timber caused by a tree growing with a twisted grain. The result is a piece of lumber or timber with surfaces at one end that are not in the same plane as the surfaces at the other end. Occasionally, usable short lengths with little twist can be cut from the original piece. More commonly, the original piece is useless.

Ultralighter (Ultralight Backpacker): A backpacker who carries the absolute minimum.

Underpass: An underground tunnel or passage enabling trail users to cross under a road or railway.

Understory: All forest vegetation growing under the canopy or upper layers of forest vegetation.

Universal Design: Few if any barriers exist to inhibit accessibility.

Universal Trail Assessment Process (UTAP): An inventory process that can be used by trail managers to assess a trail to determine compliance with design guidelines and to provide objective information to trail users regarding grade, cross slope, tread width, surface, and obstacles.

Unravel: To lose material from the edges of a retaining wall (revetment, cribbing).

Upland: Land at a higher elevation than the alluvial plain or low stream terrace; all lands outside the riparian-wetland and aquatic zones.

Urban: Places within boundaries set by state and local officials having a population of 5,000 or more.

Urban Interface: An area characterized by an intermingling of residential private land with federal lands.

Use Volume: The total volume of visitor use each segment of a travel route/trail or use area receives.

User Fee: Any charge for use of services, facilities, trails, or areas. Examples include trail use fees, entrance fees, parking fees, shelter fees, or voluntary donations.

Utility: Public utilities (electric, telephone, fiber optic, water and sewage, and gas companies) and utility-like facilities (pipelines, roads, levees, canals)

Utility Terrain Vehicle (UTV) (Mule, Side-by-Side, Dune Buggy, Recreational Utility Vehicle (RUV), Buggy, Ridge Runner): Off Highway Vehicle that exceeds the established width of an All Terrain Vehicle (ATV) but smaller than a jeep. Typically includes a side-by-side seating arrangement, roll cage, and a steering wheel as opposed to a handlebar.

Valley: A long, narrow land area lying between two areas of higher elevation, often containing a stream.

Vandalism: Malicious destruction or defacement of someone else's property.

Vegetation: Plant life; growing plants.

Vegetation, Native: Indigenous species that are normally found as part of a particular ecosystem; a species that was present in a defined area prior to European settlement.

Vestibule: Sheltered storage area adjacent to tent interior.

Viewshed: The landscape that can be directly seen under favorable atmospheric conditions from a viewpoint or along a trail corridor.

Viscosity: A measure of the resistance of a fluid to flow. For liquids, viscosity increases with decreasing temperature.

Visitor-Day, Recreation (RVD): 12 hours of recreation at a given site. One recreation visitor-day can be one person for 12 hours, 2 people for 6 hours, 12 people for 1 hour and so on. Used by agencies to count visits to developed sites, trails, and backcountry.

Visitor Use Infrastructure: Amenities such as roads, parking areas, facilities, and trails, to protect the resource and support the recreation user in their pursuit of activities, experiences, and benefits.

Visitors: Total number of people that visit an area during some unit of time, usually a year. Used by agencies to count visits to developed sites, trails, and backcountry.

Visual Foreground-Middleground: The area visible from a travel route, use area, or other observation point to a distance of 3 to 5 miles. The outer boundary of this zone is defined as the point where the texture and form of individual plants are no longer apparent in the landscape. Vegetation is apparent only in patterns or outline.

Visual Quality: The relative worth of a landscape from a visual perception point of view.

Visual Resource(s): The visible physical features on a landscape (e.g., land, water, vegetation, animals, structures, and other features).

Visual Resource Management (VRM): The inventory and planning actions taken to identify visual values and to establish objectives for managing those values; and the management actions taken to achieve the visual management objectives.

Visual Resource Management Classes: Categories assigned to public lands based on scenic quality, sensitivity level, and distance zones. There are five classes (Preservation, Retention, Partial Retention, Modification, and Rehabilitation/Enhancement). Each class has an objective which prescribes the amount of change allowed in the characteristic landscape.

Vitamin I: Ibuprofen: a pain-killer essential during the first week of a long-distance hike.

Void: An empty area or space; "the huge desert voids."

Volunteer: Person who works on a trail or for a trail club without pay.

Walk-up: A summit that can be reached without technical climbing skills, like Whitney.

Walking Distance: The distance which may be covered by a 5- to 10-minute walk, usually one-quarter to one-half mile, at an easy pace from the outer limit of a development to a transit station or activity center. Mostly used while referring to mixed-use development and trying to create a pedestrian-friendly environment.

Walkway: An area for general pedestrian use (other than a sidewalk or path) such as courtyards, plazas, and pedestrian malls.

Wall, Retaining (Revetment, Cribwall, Cribbing, Mono-wall, Multi-Tier Wall): A structure used to prevent soil from slumping, sliding, or falling; usually made of log, stone, bags, block, or pavement. Often used to provide stability and strength to the edge of a trail or stream bank.

Wall, Rubble: A roughly built wall or structure or irregular or greatly differing sizes of stone usually laid at or nearly at the same angle as the cross slope; frequently used to discourage shortcutting corners and to armor native slopes to prevent erosion.

Wall, Sutter Retaining: A patented prefabricated component retaining wall using rebar, "H" posts, and 2-inch lumber. For information call Sutter Equipment at 415-898-5955.

Wall, Wing (Wingwall): A structural component of a retaining wall, which is interlocked with the facer or front of the wall. The wing generally intersects with the facer at a 45º angle, but may be at an angle between 1 and 90º. This component is anchored by tie logs and both assists the facer in retaining the fill material, and helps prevent flanking.

Wane: A defect in a piece of lumber or timber, caused by bark that was not removed or a beveled edge.

Waney Edge: A term used at the sawmill to describe a board, plank, or timber of nonuniform width when one or two edges contain bark or irregular sapwood just below the bark. A waney edge is considered

Warp: Severe bend in a piece of lumber or timber making it unusable in its original length. Sometimes the warp occurs mostly at one point, usually a knot, and short usable pieces can be cut on either side of that point.

Wash: Removal or erosion of soil by the action of moving water. The dry bed of a stream, particularly a watercourse associated with arid environments and characterized by large, high-energy discharges with high bed-material load transport.

Wash Out: When one or both wheels (motorcycle or mountain bike) lose traction and slide toward the outside of a turn, taking the rider off course and perhaps causing a crash.

Washout: Erosion of a relatively soft surface, such as a trail, by a sudden gush of water, as from a downpour or floods. A channel produced by such erosion.

Water, Surface: All water on the surface of the Earth naturally exposed to the atmosphere, for example, rivers, lakes, reservoirs, ponds, streams, impoundments, seas, estuaries, etc., and all springs, wells, or other collectors directly influenced by surface water.

Water Course: Any natural or built channel through which water naturally flows or will collect and flow during spring runoff, rainstorms, etc.

Water Pollution: Generally, the presence in water of enough harmful or objectionable material to damage the water quality.

Water Quality: The chemical, physical, and biological characteristics of water with respect to its suitability for a particular use.

Waterbar: A drainage structure (for turning water) composed of an outsloped segment of tread leading to a barrier (log, stone, or timber) placed at a 45° angle to the trail. Water flowing down the trail will be diverted by the outslope or, as a last resort, by the barrier. This type of drainage structure is not longer recommended for construction or use on trails. Grade dips are preferred.

Waterfall: Sudden, near vertical descent of water from a height as it flows over rock or a steep embankment.

Waterlogged: A soil condition in which both large and small pore spaces are filled with water. The soil may be intermittently waterlogged because of a fluctuating water table or it may be waterlogged for short periods after rain.

Watershed (Drainage Basin, Catchment Basin): A region or area bounded peripherally by a water parting formation (i.e. ridge, hill, mountain range) and draining ultimately to a particular watercourse or body of water.

Waterway(s): The volume of water distinguishes waterways. Rivers have the greatest volume, followed by streams, creeks, and brooks.

Way (Vehicle Way): A route established and maintained solely by the passage of motor vehicles. It has not been improved and maintained by mechanical means to ensure relatively regular and continuous use.

Waypoint: A point between major points on a route, as along a track.

Wayside(s): The side or edge of a trail, road, way, path, or highway. Site(s) along a trail that allows users a place to stop to sit, rest, eat, enjoy a view, or read an informational display. They can be located where there are noteworthy natural or cultural resources, attractive views, or a lack of other nearby facilities.

Weathering: The physical and chemical disintegration and decomposition of rocks and minerals.

Weed: A plant considered undesirable, unattractive, or troublesome, usually introduced and growing without intentional cultivation.

Weed Cutters (Weed Whip, Swizzle Stick, Swing Blade): Tool with a serrated blade at the end of a wooden handle, used to clear trail corridors of succulent vegetation.

Weephole: Opening left in a retaining wall (revetment, cribbing) to allow groundwater drainage.

Weir: A depressed channel in a dam providing an outlet for the overflow water in a pond when the water level exceeds a desired height. They are usually concrete or timber, or a combination of the two. A structure to control water levels in a stream. Weir (fish trap) barrier constructed to catch upstream migrating adult fish.

Wetland(s): Lowland areas, such as a marshes or bogs that are saturated with water, creating unique habitat for plants and wildlife.

Wheel Guard (Curb Edge, Bull Rail): Narrow logs, poles, or lumber installed along the edges of bridge or puncheon decking designed to help define the edge of the structure and prevent damage to the edges of the decking material by trail users. Also to help keep wheeled equipment (wheelchair, bicycle, OHV) from running off the edge of the structure.

Wheelbarrow: A shallow open box with a wheel in front and two handles in the rear; used for moving small loads of loose material.

Wheelchair: Mobility aid, designed for and used by individuals with mobility impairments; may be manually operated or motorized.

Wheelie: A technique in which you elevate the front wheel (motorcycle or mountain bike) and ride on the rear wheel only.

White-out: Extremely heavy snow conditions with near-zero visibility. May also refer to thick fog or low-hanging clouds or dust that produce the same effect.

Width, Clearing: The outer edges of clearing areas (cleared of trees, limbs, and other obstructions) as specified by trail use.

Width, Design: The width specification that a trail was designed to meet, generally considered part of the trail (the beaten path or tread width).

Width, Minimum Clear: The narrowest point on a trail; created when significant obstacles, such as utility poles or tree roots, protrude into and reduce the design width.

Width, Tread: The width of the portion of the trail used for travel.

Wild and Scenic River: A river and adjacent lands protected under the 1968 Wild and Scenic River Act. The Act protects rivers in one of three classifications:

• Wild river areas: those rivers or sections of rivers free of impoundments and generally inaccessible except by trail, with watersheds or shorelines essentially primitive and waters unpolluted.
• Scenic river areas: those rivers or sections of rivers that are free of impoundments, with shorelines or watersheds still largely primitive and shorelines largely undeveloped, but accessible in places by roads.