US Map / Cities / Boise

Boise Map

Idaho's capital and by far its largest city sits where the Boise River leaves the mountains and spreads onto the Snake River Plain, with bare foothills at its back.

Where is Boise?

Boise is in southwestern Idaho, about 40 miles east of the Oregon line. Salt Lake City is roughly 340 miles southeast, Portland some 430 road miles northwest down the Snake and Columbia, and Seattle about 500 miles northwest. Interstate 84 is the single through route, following the same corridor the Oregon Trail used. Nothing else in Idaho comes close to Boise in size, and the state capital of any neighboring state is a full day's drive away.

Boise at a glance

Boise in Idaho

Boise is the seat of Ada County and the anchor of the Treasure Valley, the belt of towns — Meridian, Nampa, Caldwell — running west toward Oregon; the Idaho county map sets that one corner against 44 counties of mountain and rangeland, most of them nearly empty. It is Idaho's only city in the national top 100. Northern Idaho keeps Pacific Time while Boise and the southern two-thirds of the state run on Mountain Time — the Idaho state page shows where the line falls.

The Boise Front and the Snake River Plain

The city sits at the western end of the Snake River Plain, the broad volcanic arc that curves across southern Idaho, and the Boise River crosses it from the northeast to join the Snake at the Oregon border. Directly behind downtown the Boise Front rises abruptly — treeless, sagebrush foothills climbing to the forested Boise Mountains, the southwestern edge of the Rocky Mountains. That abrupt boundary puts trailheads within a few minutes of the state capitol and puts the city in the path of both wildfire and sudden runoff. Water storage in the reservoirs upstream is what allows irrigated farming across the valley below; the Snake River carries the drainage on west into Oregon.

Cities near Boise

The nearest cities of any size are Portland, Seattle, Reno and Denver — all of them hours away. Pairing Boise with Idaho is one of the harder rounds of the capitals quiz, and the West region page shows how much empty country separates these cities.