Idaho State Map

Regions of Idaho

Idaho is shaped by mountains in the north and center and by the broad, curving Snake River Plain across the south, where most Idahoans live.

North Idaho (the Panhandle)

Forested mountains and large lakes between Washington and Montana: Lake Pend Oreille, the state’s largest lake, plus Priest Lake and Lake Coeur d’Alene. Coeur d’Alene, Post Falls, Sandpoint and Bonners Ferry are the main towns. The Panhandle uses Pacific Time and is economically tied to Spokane, Washington.

North Central Idaho

Lewiston sits where the Clearwater River meets the Snake; barges reach its port from the Pacific by the Columbia and Snake rivers. Moscow, home of the University of Idaho, is in the Palouse wheat country. Grangeville is the gateway to the Clearwater and Salmon river backcountry.

Central Idaho mountains

The most rugged part of the state, crossed by few roads. The Frank Church–River of No Return Wilderness surrounds the Salmon River. The Sawtooth Range rises above Stanley, Sun Valley and Ketchum ski country lies to the south, and Borah Peak, the highest point, is in the Lost River Range to the east.

Southwest Idaho (Treasure Valley)

Boise, Meridian, Nampa and Caldwell form the state’s largest metro area along the Boise River. Ada and Canyon counties together had about 39 percent of Idaho’s 2020 population. Hells Canyon, one of the deepest river gorges in North America, follows the Snake River on the Oregon border to the northwest.

Magic Valley and Eastern Idaho

Irrigated farmland along the Snake River, the center of Idaho’s potato crop. Twin Falls overlooks the Snake River Canyon and nearby Shoshone Falls. Farther east are Pocatello, Idaho Falls and Rexburg; Craters of the Moon National Monument and Preserve protects lava fields north of the plain, and a thin strip of Yellowstone National Park lies inside Idaho’s eastern border.

Snake River and other rivers

The Snake River enters from Wyoming, arcs west across southern Idaho through Idaho Falls, American Falls and Twin Falls, then turns north to form the border with Oregon and part of the border with Washington before leaving the state at Lewiston. The Salmon River drains the central mountains, and the Clearwater and Kootenai rivers drain the north. Dams on the Snake supply irrigation water and hydropower.

Idaho county map

Idaho has 44 counties. Ada County, which includes Boise and Meridian, is the most populous (494,967 in 2020). Idaho County, a mountainous county in the north-central part of the state, is the largest by area. Turn on the county layer on the map above to see all county lines.

Major highways

• I-84: from Oregon through Caldwell, Nampa, Boise, Mountain Home and Twin Falls to Utah; I-184 is a short spur into downtown Boise.
• I-86: from I-84 east of Burley to American Falls and Pocatello.
• I-15: from Utah through Pocatello and Idaho Falls to Monida Pass on the Montana line.
• I-90: across the Panhandle from Washington through Post Falls and Coeur d’Alene to Lookout Pass and Montana.
• US 95: the main road linking south and north Idaho, through Weiser, New Meadows, Grangeville, Lewiston, Moscow, Coeur d’Alene and Sandpoint to Canada.
• US 12 and US 93: mountain routes from Lewiston over Lolo Pass and from Twin Falls through Challis and Salmon to Montana.