Geography of the United States

Major regions and landforms

• East: Atlantic coastal plains, rolling meadows and mixed grasslands, and extensive forests, interrupted by the older Appalachian Mountains.
• Interior: The Great Plains extend across the central United States and transition westward into higher relief; the continent’s largest river system, the Mississippi–Missouri network, drains much of this area.
• West: The younger, higher Rocky Mountains rise to the west of the plains; farther west are deserts and varied arid lands and broad coastal regions along the Pacific.
• North and far north: Alaska contains alpine, tundra and Arctic environments, with seasonally frozen ground and polar conditions in its far north.
• Islands: Volcanic island chains such as the Hawaiian Islands and their associated ecosystems lie far from the continental landmass; the state of Hawaii is geographically distinct from the Americas.

These broad regions are further subdivided into many local physiographic provinces (coastal plains, piedmonts, basins, plateaus and ranges). Climatic variation—from humid subtropical and continental in the interior and east to Mediterranean and maritime on parts of the west coast, and to polar in northern Alaska—shapes vegetation, soils and human land use across the country.

Geological history and development

The landscape of the United States is the product of long geological processes: ancient mountain-building events formed the Appalachians, the collision and accretion of terranes and later uplift produced the Rockies and other western ranges, and volcanic activity created island chains like Hawaii. Glacial advances in the Pleistocene carved the Great Lakes and deposited soils that today support intensive agriculture in parts of the Midwest and Northeast.

Rivers, coasts and human importance

Rivers such as the Mississippi and Missouri have historically been vital transportation corridors and remain crucial for commerce, irrigation and ecosystems. Long coastlines along both oceans support major ports, fisheries and tourism, while interior plains provide much of the nation's agricultural production.

The geographic center of the entire country (including Alaska and Hawaii) lies near Butte County in South Dakota, while the center of the contiguous 48 states is near Smith County in Kansas. These points are symbolic markers of the nation’s spatial extent and are commonly referenced in geographic descriptions and education.

Understanding the geography of the United States helps explain regional differences in climate, economy, population density and natural resources. For more detailed regional maps and descriptions see regional atlases and federal resources linked by topic here and by subject area here.