The United States occupies a broad portion of North America, bordered by Canada to the north and Mexico to the south, with the Atlantic Ocean to the east and the Pacific Ocean to the west. Alaska lies in the northwest of the continent, while Hawaii is an island state in the central Pacific. The country also includes Caribbean and Pacific territories.
Its physical geography is exceptionally varied. Major regions include the Atlantic and Gulf Coastal Plains, the Appalachian Mountains, the Interior Plains and Great Plains, the Mississippi River basin, the Rocky Mountains, intermountain deserts and plateaus, the Sierra Nevada, the Cascade Range, and Pacific coastal valleys. Alaska adds major glaciated mountains, tundra, boreal forest, and Arctic coastline, while Hawaii is defined by volcanic islands.
The country contains extensive forests, fertile agricultural plains, deserts, wetlands, prairies, mountain systems, and long coastlines. Significant river systems include the Mississippi-Missouri-Ohio network, the Colorado, Columbia, Rio Grande, and Yukon. The Great Lakes, shared with Canada, form one of the largest freshwater systems on Earth.
Natural resources include fertile soils, timber, freshwater, coal, natural gas, petroleum, copper, iron ore, and other minerals, though resource distribution varies strongly by region. Geological activity is especially notable in Alaska, California, Hawaii, and the Pacific Northwest, where tectonic boundaries drive earthquakes, volcanic risk, and mountain building.
Because of its size, the United States spans nearly every major climate type found in the mid-latitudes and tropics, from humid subtropical and humid continental climates to Mediterranean, semi-arid, desert, tundra, and tropical climates.