US Map / Regions / West

West US Map

Thirteen states covering half the country's land area and under a quarter of its people, from the Aleutians to the Rio Grande.

The 13 Western states

Half the country's land, less than a quarter of its people. The West covers about 1.75 million square miles — 49.6 percent of the national land area — and held roughly 80 million residents in 2024, about 45 people per square mile. It is the only region that includes states outside the contiguous United States, which is why Hawaii and Wyoming end up in the same statistical box.

Alaska alone accounts for 571,000 square miles of land, more than Texas and California combined. California holds 39.4 million people, close to half the region's total; Wyoming, at about 588,000, is the least populous state in the country. Both extremes are in the same region, which is the single most useful thing to know about the Census West.

Two divisions, two very different Wests

The Mountain division is the eight interior states, the emptiest division in the country at roughly 31 people per square mile. The Pacific division is just five states — the three that front the ocean in the Lower 48, plus Alaska and Hawaii — and it is the only Census division that is not geographically contiguous. The split is real rather than bureaucratic: the Mountain states are high, dry, federally owned in large part, and drained inland or to the Gulf of California, while the Pacific states face the ocean and hold two-thirds of the region's population.

• Mountain (8 states)
• Pacific (5 states)

The West's largest cities

Los Angeles is the second-largest city in the country at about 3.88 million in 2024, and Phoenix is the fifth at about 1.67 million. San Diego, San Jose, and San Francisco fill out California's top tier, and Seattle, Denver, Las Vegas, Portland, Albuquerque, and Tucson lead elsewhere. Away from those metros the region empties out fast: Anchorage is the largest city in a state that covers about a fifth as much land as the entire Lower 48, and Boise is the only top-100 city in Idaho.

Mountains, deserts, and the Pacific rim

The Rocky Mountains run from Montana to New Mexico, carrying the Continental Divide through five Western states and separating water bound for the Atlantic from water bound for the Pacific. West of the Rockies the Great Basin drains nowhere at all, ending in closed sinks including the Great Salt Lake and, at its southern end, the Mojave Desert. Along the coast the Sierra Nevada and the Cascade Range form a near-continuous wall from southern California to the Canadian border, wringing the rain out of the Pacific side and leaving the interior arid.

The rivers follow the same logic. The Colorado gathers snowmelt from Colorado, Utah, and Arizona and is so heavily allocated that it usually fails to reach the sea. The Columbia and its main tributary the Snake drain the Northwest through Washington and Oregon. The eastern edges of Montana, Wyoming, Colorado, and New Mexico sit on the Great Plains, and the whole western margin is the Pacific coast.

Census West versus the Wests people talk about

Nobody outside a statistical agency calls Hawaii and Wyoming the same region. In ordinary speech the West splits into the Pacific Northwest (Washington, Oregon, and often Idaho), the Southwest (Arizona and New Mexico with parts of Texas, Nevada, and California), the Mountain West or Intermountain West, and California treated as its own thing. Alaska and Hawaii are usually left out of "the West" altogether and described simply as the non-contiguous states. The Bureau keeps all thirteen together because the alternative is a region too small to report on; see the regions hub for how the four regions and nine divisions nest.

Keep going

East of the Rockies the Midwest takes over, the South begins at the Texas line, and the Northeast is the region the West is least like in every measurable way. The West map quiz is the drill for these thirteen states, and because the West spans four time zones the time zone map is worth a look alongside it.