Feature Class descriptions as detailed by the U.S. Board on Geographic Names.

Feature Description

Arch Natural arch-like opening in a rock mass (bridge, natural bridge, sea arch).

Area Any one of several areally extensive natural features not included in other categories (badlands, barren, delta, fan, garden).

Arroyo Watercourse or channel through which water may occasionally flow (coulee, draw, gully, wash).

Bar Natural accumulation of sand, gravel, or alluvium forming an underwater or exposed embankment (ledge, reef, sandbar, shoal, spit).

Basin Natural depression or relatively low area enclosed by higher land (amphitheater, cirque, pit, sink).

Bay Indentation of a coastline orshoreline enclosing a part of a body of water; a body of water partly surrounded by land (arm, bight, cove, estuary, gulf, inlet, sound).

Beach The sloping shore along a body of water that is washed by waves or tides and is usually covered by sand or gravel (coast, shore, strand).

Bench Area of relatively level land on the flank of an elevation such as a hill, ridge, or mountain where the slope of the land rises on one side and descends on the opposite side (level).

Bend Curve in the course of a stream and (or) the land within the curve; a curve in a linear body of water (bottom, loop, meander).

Cape Projection of land extending into a body of water (lea, neck, peninsula, point).

Cave Natural underground passageway or chamber, or a hollowed out cavity in the side of a cliff (cavern, grotto).

Channel Linear deep part of a body of water through which the main volume of water flows and is frequently used as aroute for watercraft (passage, reach, strait, thoroughfare, throughfare).

Cliff Very steep or vertical slope (bluff, crag, head, headland, nose, palisades, precipice, promontory, rim, rimrock).

Crater Circular-shaped depression at the summit of a volcanic cone or one on the surface of the land caused by the impact of a meteorite; a manmade depression caused by an explosion (caldera, lua).

Falls Perpendicular or very steep fall of water in the course of a stream (cascade, cataract, waterfall).

Flat Relative level area within a region of greater relief (clearing, glade, playa).

Forest Bounded area of woods, forest, or grassland under the administration of a political agency (see "woods") (national forest, national grasslands, State forest).

Gap Low point or opening between hills or mountains or in a ridge or mountain range (col, notch, pass, saddle, water gap, wind gap).

Glacier Body or stream of ice moving outward and downslope from an area of accumulation; an area of relatively permanent snow or ice on the top or side of a mountain or mountainous area (icefield, ice patch, snow patch).

Gut Relatively small coastal waterway connecting larger bodies of water or other waterways (creek, inlet, slough).

Harbor Sheltered area of water where ships or other watercraft can anchor or dock (hono, port, roads, roadstead).

Island Area of dry or relatively dry land surrounded by water or low wetland (archipelago, atoll, cay, hammock, hummock, isla, isle, key, moku, rock).

Isthmus Narrow section of land in a body of water connecting two larger land areas.

Lake Natural body of inland water (backwater, lac, lagoon, laguna, pond, pool, resaca, waterhole).

Lava Formations resulting from the consolidation of molten rock on the surface of the Earth (kepula, lava flow).

Pillar Vertical, standing, often spire-shaped, natural rock formation (chimney, monument, pinnacle, pohaku, rock tower).

Plain A region of general uniform slope, comparatively level and of considerable extent (grassland, highland, kula, plateau, upland).

Range Chain of hills or mountains; a somewhat linear, complex mountainous or hilly area (cordillera, sierra).

Rapids Fast-flowing section of a stream, often shallow and with exposed rock or boulders (riffle, ripple).

Ridge Elevation with a narrow, elongated crest which can be part of a hill or mountain (crest, cuesta, escarpment, hogback, lae, rim, spur).

Sea Large body of salt water (gulf, ocean).

Slope A gently inclined part of the Earth's surface (grade, pitch).

Spring Place where underground water flows naturally to the surface of the Earth (seep).

Stream Linear body of water flowing on the Earth's surface (anabranch, awawa, bayou, branch, brook, creek, distributary, fork, kill, pup, rio, river, run, slough).

Summit Prominent elevation rising above the surrounding level of the Earth's surface; does not include pillars, ridges, or ranges (ahu, berg, bald, butte, cerro, colina, cone, cumbre, dome, head, hill, horn, knob, knoll, mauna, mesa, mesita, mound, mount, mountain, peak, puu, rock, sugarloaf, table, volcano).

Swamp Poorly drained wetland, fresh or saltwater, wooded or grassy, possibly covered with open water (bog, cienega, marais, marsh, pocosin).

Valley Linear depression in the Earth's surface that generally slopes from one end to the other (barranca, canyon, chasm, cove, draw, glen, gorge, gulch, gulf, hollow, ravine).