Glossary of Trail and

 Greenway Terms

Abney Level: Hand-held instrument that is adjusted like a sextant and used for measuring angles of elevation or inclination of trail. 

Abutment: Structure at either extreme end of a bridge that supports the superstructure (sill, stringers, trusses, or decks) composed of stone, concrete, brick, or timber. 

Access Points: Designated areas and passageways that allow the public to reach a trail from adjacent streets or community facilities. 

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

Accessible: A term used to describe a site, building, facility, or trail that complies with the Americans with Disabilities Act (ADA) Accessibility Guidelines and can be approached, entered, and used by people with disabilities. 

Acclimatization: The gradual process of becoming physiologically accustomed to high altitude.   

Acquisition: The act or process of acquiring fee title or interest of real property.   

Acute Mountain Sickness (AMS): A condition characterized by shortness of breath, fatigue, headache, nausea, and other flulike symptoms. It occurs at high altitude and is attributed to a shortage of oxygen. Most people don’t experience symptoms until they reach heights well above 5,000 feet. 

Adopt-A-Trail: A program in which groups or businesses “adopt” trails, providing volunteer work parties at periodic intervals to help maintain the trail. Though no special trail privileges are granted, the trail manager generally acknowledges that a trail has been “adopted” by erecting signs saying the trail is part of an Adopt-A-Trail program and including the name of the adopter. 

Adz (Adze): An ax-like tool for dressing wood. 

Aggregate: Surface material made up of broken stone ranging in size from broken stone or gravel to sand. 

Alignment: The layout of the trail in horizontal and vertical planes. This is to say, the bends, curves, and ups and downs of the trail. The more the alignment varies, the more challenging the trail. 

All-Terrain-Vehicle (ATV): A small four-wheeled vehicle equipped with low-pressure balloon tires and intended for off-highway use only. 

Altimeter: An instrument for measuring altitude. 

Altitude: The height of a thing or place above sea level. 

Amenities: Any element used to enhance the user’s experience and comfort along a trail. 

Americans with Disabilities Act of 1990 (ADA): A federal law prohibiting discrimination against people with disabilities. Requires public entities and public accommodations to provide accessible accommodations for people with disabilities. 

Americans with Disabilities Act Accessibility Guidelines (ADAAG): Design guidelines for providing access to a range of indoor and outdoor settings by people with disabilities. 

Angle: Angle is measured with a straight vertical as 90º and a straight horizontal as 0º. A grade of 100% would have an angle of 45º. 

Appraisal: An estimate and opinion of value, usually a written statement of (1) the market value of (2) an adequately described parcel of property as of (3) a specified date. 

Apron: One of the three main elements of a waterbar. It catches water running down the trail and directs it off. Apron is also the transition area on a switchback (also called the “landing”). 

Arborist: An individual trained in arboriculture, forestry, landscape architecture, horticulture, or related fields and experienced in the conservation and preservation of native and ornamental trees. 

Archaeological Resources (Cultural, Heritage): Any material of past human life, activities, or habitation that are of historic or prehistoric significance. Such material includes, but is not limited to, pottery, basketry, bottles, weapon projectiles, tools, structures, pit house, rock paintings, rock carving, graves, skeletal remains, personal items and clothing, household or business refuse, or any piece of the foregoing. 

Archaeological Site: A concentration of material remains of past human life or activities that is of historic or prehistoric significance and that has been surveyed by a qualified archeologist. 

Armoring: Reinforcement of a surface with rock, brick, stone, concrete, or other “paving” material. 

Aspect: The particular compass direction a trail or site faces. Aspect affects the amount of solar radiation and year-round moisture to which a site is subjected. 

Asphalt (Macadam): Petroleum-based surface material that provides a smoothly paved surface that is suitable for bicycles and in-line skates. It is preferred in urban areas where trails are often used for commuting to and from work or school. 

Assessment, Trail or Corridor: Physical assessments are undertaken to better understand a trail or corridor. Assessments include an accurate description and documentation of native elements and an inventory of built structures along the trail or corridor. 

At-Grade Crossing: A trail crossing a roadway on the same elevation. Ideally, a safe at-grade crossing has either light automobile traffic or a traffic signal that can be activated by trail users. 

Axe (Ax): A tool with a long handle and bladed head (single bit – one sharp side or double bit – two sharp sides) for chopping deadfall from trails, shaping stakes for turnpikes and waterbars, and cutting notches for structures made of timber.

B

Backcountry: An area where there are no maintained roads or permanent buildings—just primitive roads and trails. 

Backcut: The vertical part of a bench cut that is blended into the backslope. 

Backfill: Material used to refill a ditch or other excavation, or the process of doing this action. 

Backpack: A large pack worn on the back to carry camping supplies; to go on an overnight hike carrying your supplies in a backpack. 

Backslope: The cut bank along the uphill side of the trail extending upward from the tread. Usually sloped back by varying degrees, depending on bank composition and slope stability. 

Bald: Mountain with an open, grassy summit that’s void of trees. 

Ballast: Stone, cinders, gravel, or crushed rock fill material used to elevate a railroad bed above the surrounding grade, to provide proper drainage and a level surface for the ties and rails.   

Bar: A sand or gravel deposit in a streambed that is often exposed only during low water periods.

Bark Spud: A tool with a 1- to 4-foot long wood handle and a dished blade used to remove bark from logs by sliding between the bark and the wood. 

Barricade: A portable or fixed barrier having object markings, used to close all or a portion of the trail right-of-way to trail traffic. 

Barrier-Free Design: A trail design that promotes the elimination of physical barriers that reduce access to areas by people with disabilities. 

Base: The primary excavated bed of a trail upon which the tread, or finished surface lies. 

Base Course: The layer or layers of specified material of designed thickness placed on a trailbed to support surfacing. 

Base Map: A map showing the important natural and built features of an area. Such maps are used to establish consistency when maps are used for various purposes. 

Batter: The angle an abutment or rock wall is inclined against the earth it retains. 

Bed: The excavated surface on which a trail tread lies. 

Bedrock: Solid rock material that is exposed when topsoil is eroded or cut away. 

Bench: A long (with or without a back) seat for two or more people. 

Bench Cut: A relatively flat, stable surface (tread) on a hillside occurring naturally or by excavation. When excavated often referred to as full or half bench. 

Bent: Structural member or framework used for strengthening a bridge or trestle transversely. 

Berm: The ridge of material formed on the outer edge of the trail that projects higher than the center of the trail tread. 

Bike Path (Bike Trail, Bikeway, Multiuse Path/Trail): Any corridor that is physically separated from motorized vehicular traffic by an open space or barrier. It is either within the highway right-of-way or within an independent right-of-way. Due to a lack of pedestrian facilities, most bike paths/trails are commonly designed and referenced as multiuse paths and trails. 

Biodegradable: Able to decompose when exposed to biological agents and soil chemicals.

Birdcage: Wire rope that has begun to unwrap individual strands of wire. 

Bivouac: A night out without a tent. 

Bivouac Sack (Bivy Sack): A lightweight, unfilled, waterproof bag that can cover a sleeping bag. 

Blaze: A trail marker. Blazes can be made on a tree by chipping away a piece of the bark and painting the chipped out part with a 2-inch by 6-inch, vertical rectangle. Plastic triangles or diamonds (known as blazers) with the name of the trail or a directional arrow imprinted can be purchased and nailed to trees to mark a trail route. 

Blaze, Blue/White: On the Appalachian Trail a blue blaze almost always means a side trail to a campsite or a town. White blazes are generally used for the main or trunk trail. Many other trails follow the Appalachian Trail example. 

Blaze, Double: Two blazes (vertical alignment) that denote a change in direction or junction in the trail coming up. 

Bleeder (Kick Outs, Diversion Dips): Graded depression angled to drain water sideways off the treadway. 

Blister: A thin, round swelling of the skin, filled with water, caused by rubbing. 

Block: Pulley in which a rope or cable is threaded. 

Block, Snatch: Pulley with hinged side plate allowing attachment anywhere along a fixed rope. 

Blowdown (Windfall): Anything (trees, limbs, brush, etc.) blown down on the trail by the wind. 

Bluff: A steep headland, promontory, riverbank, or cliff. 

Boardwalk: A fixed planked structure, usually built on pilings in areas of wet soil or water to provide dry crossings. 

Bog Bridge: See Puncheon. 

Bogs: A muddy area common where little direct sunlight reaches the trail or where there are flat areas that are difficult to drain. 

Bollard: A barrier post, usually 30 to 42 inches in height, used to inhibit vehicular traffic at trail access points. 

Borrow: Fill material required for on-site trail construction and obtained from other nearby locations. 

Borrow Pit: Area where soil, gravel, or rock materials are removed to be used on the trail for tread, embankments, or backfilling. 

Bow Saw: A 16-, 21-, or 36-inch thin bladed saw with a curved handle used to cut brush or trimming small branches. 

Braiding (Braided Trail): The process of numerous routes being created. Identified by worn and eroded vegetation. 

Bridge: A structure, including supports, erected over a depression (stream, river, chasm, canyon, or road) and having a deck for carrying trail traffic. If the structure is two feet above the surface the bridge should have railings. 

Bridleway (Bridle Path): Public way designed and maintained primarily for equestrian use. Other nonmotorized uses may be permitted. 

Brush: Vegetation or small flora. 

Brushing: To clear the trail corridor of plants, trees, and branches which could impede the progress of trail users. 

Brushing-In (Obliteration): To pile logs, branches, rocks, or duff along the sides of the tread to keep users from widening the trail, or to fill in a closed trail with debris so that it will not be used. 

Buffer (Buffer Zone): Any type of natural or constructed barrier (like trees, shrubs, or wooden fences) used between the trail and adjacent lands to minimize impacts (physical or visual). 

Burns: (Formerly called “controlled burns,” now called “prescribed burns.”) These are periodic intentional fires conducted by forestry services to clear underbrush in an effort to control “wildfires,” open areas to wildlife, and promote germination of some species of flora. 

Bush Hook: A long handle and either double- or single-edged curved blade gives the bush hook a powerful cut. 

Bushwhack: Term applied to off-trail hiking (originally where the going was difficult, where many bushes had to be whacked). Now it is often used to mean off-trail travel regardless of whether the going is difficult or not.

C

Cable, Wire: A thick, heavy rope, made of wire strands. 

Cable Fly Zone: The hazardous area a cable can potentially move to when it comes under tension or is suddenly released from tension. 

Cable Gripper: A device that clamps onto a cable when tension is applied to the attachment point/jaws. 

Cable Strap: A pre-cut length of wire rope that may have eyes on both ends which is used in rigging applications. 

Cache: A supply of food or tools, usually buried or hidden. 

Cairn: A constructed mound of rock located adjacent to a trail used to mark the trail route. Used in open areas where the tread is indistinct. 

Call Box: An emergency telephone system installed along a trail with direct connection to the local 911 network. 

Camping: Site where overnight stays are permitted. 

Canal: An artificial waterway for transportation or irrigation. 

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

Canopy: The leaf cover in a forest stand, consisting of its upper layers.

Carabiner: An oblong metal clip with a spring gate used to attach slings to ropes or ropes to anchors. 

Carrying Capacity: In a broad, generic sense it refers to the amount of use a given resource can sustain before an irreversible deterioration in the quality of the resource begins to occur. 

Catch Point: The outer limits of a trailway where the excavation and/or embankment intersect with the ground line. 

Categorical Exclusion (CE): A technical exclusion for projects that do not result in significant environmental impacts. Such projects are not required to prepare environmental reviews. 

Causeway: Elevated section of trail contained by rock, usually through permanent or seasonally wet areas. 

Center Line: An imaginary line marking the center of the trail. During construction, the center line is usually marked by placing a row of flags or stakes (to indicate where the center of the trail will be). 

Certification: The process by which sites and segments of national historic (and some national scenic) trails are officially recognized by the administering federal agency. 

Chain Saw: A portable gas-operated saw with an endless chain carrying cutting teeth. 

Charrette: A public design workshop in which designers, property owners, developers, public officials, environmentalists, citizens, and other persons or group of people work in harmony to achieve an agreeable trail or greenway project. 

Check Dam: Log, rock, or wood barrier placed across deeply eroded trails or erosional channels to slow the flow of water to allow accumulation of fine fill material behind the structure to fill in the trail tread. 

Chigger (Redbug): The tiny, red larva of certain mites, whose bite causes itching and red welts. 

Choker: Loop of rope or cable cinched onto a load so it gets tighter, or “chokes” the load under pressure. 

Chromated Copper Arsenate (CCA): Is the well-known wood preservative for boardwalks, decks, and other common trail applications where treated lumber is used. 

Circle of Danger: The area surrounding the trail worker that is unsafe due to tool use. The inner (or primary) circle of danger is the area the tool can reach while being used. The outer circle of danger is the area the tool could reach if the trail worker lost control or let go of the tool. 

Classification: The designation indicating intended use and maintenance specifications for a particular trail. 

Clearcut (Clear-cutting): Removal of all trees and shrubs, not just mature growth. 

Clearing: Removal of windfall trees, uproots, leaning trees, loose limbs, wood chunks, etc. from both the vertical and horizontal trail corridor. 

Clearing Height (Vertical Clearance): The vertical dimension which must be cleared of all tree branches and other obstructions that would otherwise obstruct movement along the trail. 

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

Clevis (Shackle): A U-shaped metal piece with holes in each end through which a pin or bolt is run. Used to attach two objects together. 

Climbing Turn: A turn which is constructed on a grade of 20% or less when measured between the exterior boundaries of the turn and follows the grade as it changes the direction of the trail 120 to 180 degrees. 

Clinometer: A hand-held instrument used for measuring angles of terrain elevation or percent of trail grade. 

Cobble (Cobblestone): Loose rock over 2 ½ inches in diameter. 

Col: A pass between two mountain peaks; or a low spot in a mountain ridge. 

Collector Ditch: A drainage structure that intercepts water flowing toward a trail and usually channeled underneath the trail through a culvert. 

Come-along: A strong cable fitted with a ratchet to gain mechanical advantage for moving heavy objects over the ground with comparative ease. It is often used in trail work to move large rocks or bridge timbers. 

Compacted: The degree of consolidation that is obtained by tamping with hand tools or by tamping mineral soil and small aggregate in successive layers not more than 6” in depth. 

Compaction: The compression of aggregate, soil, or fill material by tamping. 

Compass: A direction-finding device that is used with a map to plot a route or check your position. 

Concrete: A composition of coarse and fine aggregates, portland cement, and water, blended to give a hard, unyielding, nearly white pavement which can be finished to any degree of smoothness. Concrete us most often used in urban areas with anticipated heavy use or in areas susceptible to flooding. 

Condemnation: The taking of private property by a government unit for public use, when the owner will not relinquish it through sale or other means; the owner is compensated by payment of market value. The power to take the property is based on the concept of eminent domain. 

Conflict Resolution: Resolution is an outcome that develops from complete analysis and meets the needs of all concerned parties. Inherent in the process is clear and open communication, mutual respect, shared exploration, an orientation to collaborative problem solving, and a commitment to resolution. 

Connectivity: The ability to create functionally contiguous blocks of land or water through linkage or similar ecosystems or native landscapes; the linking of trails, greenways, and communities. 

Conservation: Controlled use and protection of natural resources. 

Construction: Building a trail where no trail previously existed. 

Contour Lines: A line on a topographic map connecting points of the land surface that have the same elevation. 

Contour Trail: Trail constructed such that it follows a contour, with it’s elevation remaining constant. 

Control Points (Targets): Features that trail users will want to naturally head towards or try to avoid (views, obstacles, etc.). These features should be flagged and used to help layout a trail. 

Corduroy: A rustic form of puncheon using native logs (3 to 5’ in length) laid parallel on wet saturated ground and covered with a tread of soil. Corduroy typically rots out quickly. 

Corridor, Scenic: Land set aside on either side of a trail to act as a buffer zone protecting the trail against impacts such as logging or development which would detract from the quality and experience of a trail. 

Corridor, Trail: The full dimensions of a route, including the tread and a zone on either side (usually three feet) and above the tread from which brush will be removed. 

Course: An even layer of stones, similar to a course of bricks, that forms a foundation, intermediate layer, or cap stone layer in a stonewall.   

Cover (Ground Cover): Vegetation or other material providing protection to a surface: area covered by live above ground parts of plants.

Cradle Timber: A mid-span timber used to transfer the load of the bridge to the truss system. 

Creek: Those areas where surface waters flow sufficiently to produce a defined channel or bed.   

Creep: Slow mass movement of soil down relatively steep slopes, primarily by gravity and water.

Cribbing (Cribwall, Retaining Wall): Rock or log reinforcement structure to support trail tread or retain backslope along steep trails that are at risk from erosion. 

Critical Point: The outside edge of the trail. It’s called the critical point because this is where trail maintenance problems (always related to drainage) usually begin. Rounding the outside edge helps water to leave the edge of the trail. 

Cross Section (Typical Cross Section or Typical): Diagrammatic presentation of a trail or path profile which is at right angles to the centerline at a given location. 

Crosscut Saw: A long saw that was favored a century ago by loggers felling trees. Used today in federally designated Wilderness Areas or by those who prefer not to use chainsaws. 

Crosswalk: Any portion of a roadway distinctly indicated for pedestrian crossing by lines or other markings on the surface. 

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

Crusher Fines (Crusher Run, Crushed Stone): Refers to any limestone, granite, or gravel that has been run through a crusher that is used to form a hard tread surface which once wetted and compacted creates a smooth trail surface for high-use areas. 

Culvert, Cross Drainage: Pipelike or boxlike construction of wood, metal, plastic, or concrete that passes under a trail to catch surface water from side ditches and direct it way from a trail. 

Culvert, Stream Bed: Pipelike or boxlike construction of wood, metal, plastic, or concrete that passes under a trail to convey a stream under a crossing without constricting waterflow. 

Curb Cut: A cut in the curb where a trail crosses a street. The curb cut should be the same width as the trail. 

Curvilinear: A free-flowing movement pattern characterized by the general absence of straight trail segments. 

Cushion Material: Native or imported material, generally placed over rocky sections of unsurfaced trail to provide a usable and maintained traveled way. 

Cut and Fill: The process of removing soil from one area and placing it elsewhere to form a base for any given activity.

Cut Slope: An earthen slope that is cut. For example, a trail built lower than the existing terrain would result in a cut slope.

D

Day Pack: A soft pack smaller than a backpack, favored by day hikers for carrying food, water, and other supplies. 

Daylighting: Clearing a ditch or drain so that water can run all the way to daylight. 

Deadfall: A tangled mass of fallen trees or branches. 

De-berming: Removing the ridge of material formed on the outer edge of the trail which projects higher than the center of the trail tread, allowing water to once again flow off the trail. 

Debris: Any undesirable material that encroaches on a trail that hinders the intended use. 

Decking (Flooring): That part of a bridge, puncheon, or boardwalk structure that provides direct support for trail traffic. 

Declination: The measurement describing the difference between true north and magnetic north. 

DEET: (chemical name N, N-diethyl-meta-toluamide) is the active ingredient used in many insect repellents. It is used to repel biting pests such as mosquitoes and ticks. 

Dehydration: A depletion of body fluids that can hinder the body’s ability to regulate its own temperature. 

Designated Trail: A trail that is approved and maintained by an agency. 

Difficulty Rating: A subjective rating of trail difficulty based on an average user with average physical abilities. For example the US Forest Service uses Easy, More Difficult, Most Difficult. Many other agencies use the following:

• Easy is defined as relaxing, posing minimal difficulties and able to be traveled with little physical effort.

• Moderate is defined as not requiring excessive or extreme physical effort.         

• Difficult is defined as physically strenuous requiring excessive or extreme physical effort. 

Digging-Tamping Bar: A long bar with a small blade at one end for loosening compacted or rocky soil and a flattened end for tamping. 

Dike (Tramway, Tram, Levee): An embankment or dam made to prevent flooding by the sea, a river/stream, or lake. The embankment is often used for a trail. 

Dispersed Recreation: Recreation activities that occur outside of developed recreation facilities away from traveled roads. Also referred to as backcountry recreation. 

Ditch: A long, narrow trench used to improve drainage. 

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

Ditching, Sidehill: A ditch which parallels the treadway on the uphill side to collect water seeping into the trail, usually ends in a drainage ditch which allows the water to cross the trail. 

Double-Track Trail: A trail that allows for two users to travel side by side or make passes without one user having to yield the trail. Double-track trails are often old forest roads. 

Down and Out: The correct position of a carabiner gate when it is connected to an anchor. 

Down Tree: Fallen tree that blocks the trail. 

Downslope: The downhill side of the trail. Avoid damaging downslope vegetation that is stabilizing hillside soil. 

Drain, Cobble: A cobbled improvement to the trail surface that allows drainage (usually from an intermittent wet seep) across the trail for continued passage along the trail without damage to the soil. 

Drainage, Cross: Running water in swamps, springs, creeks, drainages, or draws that the trail must cross. 

Drainage, Sheet: Desirable condition in which water flows in smooth sheets rather than rivulets; shower flow and less concentration results in less erosion. 

Drainage, Surface: Rain or snow runoff from the surface of the tread. 

Drainage Dip: An erosion-control technique that reverses the grade of a trail for a distance of 15-20 feet before returning to the prevailing grade. The abrupt change in grade forces water to run off the trail tread, rather than gaining additional velocity. 

Drainage Ditch (Ditching): Open ditches running parallel to the trail tread that collect water and carry it away from the site. A drainage ditch is also an element of a waterbar, providing an escape route for water diverted from the trail by the bar. 

Drains, French: These are stone filled ditches that can have a porous pipe laid along the base to collect the water and carry it away from the site. The top must be kept clear of the surfacing material; water must run freely into the drain. 

Drawings: Documents showing details for construction of a trail or trail-related facility, including but not limited to straight-line diagrams, trail logs, standard drawings, construction logs, plan and profile sheets, cross-sections, diagrams, layouts, schematics, descriptive literature, and similar materials. 

Drawknife: A tool with a sharp blade and handles at both ends used to strip bark from small-diameter logs. 

Drinking Water: Water that is “potable” or safe to drink. 

Drop-off: Slope that falls away steeply. 

Duff (Humus): A layer of decaying organic plant matter (leaves, needles, and humus) on the ground. It is highly absorbent and quickly erodes under traffic.

Dunes: Ridges or mounds of loose, wind-blown material, usually sand.

E

Easement: Grants the right to use a specific portion of land for a specific purpose or purposes. Easements may be limited to a specific period of time or may be granted in perpetuity; or the termination of the easement may be predicated upon the occurrence of a specific event. An easement agreement survives transfer of landownership and is generally binding upon future owners until it expires on its own terms. 

Easement, Charter: An easement dedicated to a specific public purpose and which is established by a private given power to condemn under a state or the federal government’s powers of eminent domain. 

Easement, Conservation: Places permanent restrictions on property in order to protect natural resources. 

Easement, Construction: An additional area or corridor needed to construct a trail or facility. 

Easement, Maintenance: An additional area or corridor (not open to the public) needed to maintain trail drainage, foliage, and recurring maintenance needs. 

Easement, Recreation: Provides public access to private property while limiting or indemnifying the owner’s public liability. 

Easement, Scenic: Places permanent restrictions on a property in order to protect the natural view. 

Ecosystem: A system formed by the interaction of living organisms, including people, with their environment. 

Ecotourism: Purposeful travel to natural areas to understand the culture and natural history of the environment, taking care not to alter the integrity of the ecosystem, while producing economic opportunities that make the conservation of natural resources beneficial to local people. 

Elevation: The height of a place above sea level. 

Elliptical Triangle (Pregnant Triangle): Shape of signs for trails in the National Trails System. 

Embankment: Structure made from soil used to raise the trail, railbed, or roadway above the existing grade. 

Eminent Domain: The authority of a government to take (usually by purchase) private property for public use. 

Endangered Species: A species of animal or plant is considered to be endangered when its prospects for survival and reproduction are in immediate jeopardy from one or more causes. 

Enhancement Funds: Under TEA-21, independent funds for bicycling and walking facilities, rail-trails, and eleven other activities. 

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

Environmental Assessment (EA): A document prepared early in a planning process (Federal) that evaluates the potential environmental consequences of a project or activity. An assessment includes the same topical areas as an EIS, but only assesses the effects of a preferred action, and in less detail than an EIS. An EA results in a decision, based on a assessment of the degree of impact of an action, that an EIS is necessary, or that an action will have no significant effect and a finding of no significant impact (FONSI) can be made. 

Environmental Education: Activities that use a structured process to build knowledge, in students and others, about environmental topics. 

Environmental Impact Statement (EIS): An EIS is a full disclosure, detailed report which, pursuant to Section 102(2)C of the National Environmental Policy Act (NEPA), establishes the need for the proposed action, identifies alternatives with the potential to meet the identified need, analyzes the anticipated environmental consequences of identified alternatives, and discusses how adverse effects may be mitigated. An EIS is prepared in two stages: a draft statement which is made available to the public for review and a final statement which is revised on the basis of comments made on the draft statement. 

Ephemeral (Creek): A temporary or short-lived water flow, especially after a heavy rain. Most of the year it’s a dry creek bed. 

Erosion: Natural process by which soil particles are detached from the ground surface and moved downslope, principally by the actions of running water. The combination of water falling on the trail, running down the trail, and of freezing and thawing, and the wear and tear from traffic create significant erosion problems on trails. 

Erosion Control: Techniques intended to reduce and mitigate soil movement from water, wind, and trail user traffic. 

Erosion, Sheet: The removal of a fairly uniform layer of soil material from the land surface by the action of rainfall and runoff water. 

Escarpment: An inland cliff formed by the erosion of the inclined strata of hard rocks. 

Exposure: The relative hazard encountered when one takes into consideration obstacles, alignment, grade, clearing, tread width, tread surface, sideslope, isolation, and proximity to steep slopes or cliffs. 

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

F

Facer: Structural member in retaining walls and abutments that is placed at right angle to the structure or trail tread. 

Fall Line: Direction water flows down a hill. A high use trail should never be constructed on the fall line of a hill.   

Fascines (Wattles): Stems and branches of rootable material (willow, dogwood, or alder for example) that are tied together in long bundles, placed in shallow trenches on contour between rock masses that have shifted.

Fauna: The animal populations and species of a specified region. 

Fee Simple Absolute: An interest in land in which the owner is entitled to the entire property without limitation or restriction, and with unconditional power of disposition. 

Fee Simple Determinate: Similar to Fee Simple Absolute, but states condition(s) under which the property will revert to the original owner/grantor. 

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

Fen: Low, flat, marshy land or a bog. 

Fence: A constructed barrier of wood, masonry, stone, wire, or metal, erected to screen or separate areas. 

File: A hand-held 10- to 12-inch flat steel tool with a rough, ridged surface for smoothing or grinding. 

Fill (Material): Gravel or soil used to fill voids in trail tread and to pack behind retaining walls and other structures. 

Fill Slope: Area of excavated material cast on the downslope side of trail cut (also called embankment). 

Fines, soil: Smallest soil particles important for binding the soil together; silt; fines are often the first particles to move when erosion takes place. 

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

Firebreak: A strip of forest or prairie land cleared or plowed to stop or prevent the spread of fire. 

Fiscal Year (FY): Annual schedule for keeping financial records and for budgeting funds. The Federal fiscal year runs from October 1 through September 30, while most state fiscal year’s run from July 1 through June 30. 

Fixed Rope (Cable): A rope or cable that is set in place to assist in moving large objects. 

Flagging: Thin ribbon used for marking purposes during the location, design, construction, or maintenance of a trail project. 

Flagline: Flagging tied to trees indicating the intended course of a trail prior to construction. 

Flags, Wire: Wire wands with square plastic flags at one end for field layout and marking of new trail or relocations of trail sections. 

Floodplain: The flat, occasionally flooded (100-year floods) area bordering streams, rivers, or other bodies of water susceptible to changes in the surface level of the water.