The names and definitions of all feature classes represented in the BGN's Geographic Names Information System (GNIS) for domestic names.
The table below shows all feature classes catalogued in the GNIS, their definitions, and examples of generic names associated with the feature class in alphabetical order.
| Feature Class | 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 | Colloquial usage in southwestern United States. The valley of an ephemeral stream with a flat floor and steep banks or the ephemeral stream flowing through a valley with a flat floor and steep banks, either hydrographic or hypsographic (draw, wash, gully). |
| 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 or shoreline 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 level to gently sloping 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 (first bottom, flood-plain step, level, terrace, tread). |
| 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). |
| Canal | Waterway, primarily manmade, used by watercraft or for drainage, irrigation, mining, or waterpower (ditch, lateral, sluice). |
| Cape | Projection of land extending into a body of water (lea, neck, peninsula, point). |
| Census | A statistical area delineated locally specifically for the tabulation of Census Bureau data (census designated place, census county division, unorganized territory, various types of American Indian/Alaska Native statistical areas). Distinct from Civil and Populated Place. |
| Channel | Linear deep part of a body of water through which the main volume of water flows and is frequently used as a route for watercraft (passage, reach, strait, thoroughfare, throughfare). Not a Stream or Valley. |
| Civil | A political division formed for administrative purposes (borough, county, incorporated place, municipio, parish, town, township). Distinct from Census and Populated Place. |
| Cliff | Very steep or vertical slope on one side (bluff, crag, escarpment, head, headland, nose, palisades, precipice, promontory, rim, rimrock, scarp). |
| 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 (bowl, caldera, lua, maar). |
| Crossing | A place at which a river or stream may be crossed (landing, ferry, ford). |
| 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, pan, park, playa lake, salina, upland) |
| 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). |
| 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, oxbow, pond, pool, resaca, tank, tarn, waterhole). |
| Lava | Formations resulting from the consolidation of molten rock on the surface of the Earth (kepula, lava flow, māwae, traps). |
| Levee | Natural or manmade embankment flanking a stream (bank, berm). |
| Military | Place or facility used for various aspects of or relating to military activity. |
| Pillar | Vertical, standing, often spire-shaped, natural rock formation (chimney, hoodoo, monument, pinnacle, pōhaku, rock tower). |
| Plain | A region of general uniform slope, comparatively level and of considerable extent; can refer to the flat area of a large mesa (desert, grassland, highland, kula, plateau, savanna). |
| Populated Place | Place or area with clustered or scattered buildings and a permanent human population (city, settlement, town, village). A populated place is usually not incorporated and by definition has no legal boundaries. However, a populated place may have a corresponding "civil" record, the legal boundaries of which may or may not coincide with the perceived populated place. Distinct from Census and Civil classes. |
| Range | A single mass of hills or mountains; a complex, interconnected series of mountain ranges having a well-defined longitudinal trend (cordillera, mountain belt, sierra). |
| Rapids | Fast-flowing section of a stream with turbulent flow, often shallow and with exposed rock or boulders, wheredischarge is mostly influenced by velocity rather than width and depth (dalles, riffle, ripple). |
| Reservoir | Artificially impounded body of water (lake, tank). |
| Ridge | Elevation with a narrow, elongated crest that can be part of a hill or mountain (arête, crest, chenier, cuesta, divide, esker, hogback, mogote, lae, ridge, 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, awāwa, 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; can occur as a single isolated mass or in a group (ahu, ballon, berg, bald, butte, cerro, colina, cone, cumbre, dome, head, hill, horn, knob, knoll, mauna, mesa, mesita, mound, mount, mountain, peak, puʻu, rock, sugarloaf, table, volcano). |
| Swamp | Poorly drained wetland, fresh or saltwater, wooded or grassy, possibly covered with open water (bog, cienega, everglades, fen, marais, marsh, pocosin, slough). |
| Valley | Linear depression in the Earth's surface that generally slopes from one end to the other (barranca, canyon, chasm, cirque, cove, coulee, draw, fjord, glen, gorge, gulch, gulf, gully, hollow, ravine). |
| Woods | Small area covered with a dense growth of trees; does not include an area of trees under the administration of a political agency. |
Note: Until 2021, the Geographic Names Information System also contained administrative and manmade feature classes such as Airport, Bridge, Building, Cemetery, Church, Dam, Forest, Harbor, Hospital, Mine, Oilfield, Park, Post Office, Reserve, School, Tower, Trail, Tunnel, and Well. These features are no longer in GNIS. Please see the Download GNIS Data page to learn how to access legacy data that utilizes these feature classes.