Butte County, Idaho

Butte County is a small and remote corner of Idaho’s high desert, with many travelers passing through without stopping. The dramatic Lost River Range rises to the west, while Arco, the county seat, is famous for its claim as the first town in the world lit by atomic power.

In some parts of the county, you may see more antelope than people, highlighting just how sparsely populated the region is. Nearby Craters of the Moon National Monument features an otherworldly landscape of ancient lava flows, volcanic craters, and cinder cones, making it one of the area’s most unusual natural attractions.

Ranching remains an important part of life in Butte County, despite the challenging climate. Summers can be extremely hot, while winters are often harsh and bitterly cold. The Big Lost River adds another unusual feature, disappearing beneath the lava plains rather than reaching a larger river system. That feeling of isolation and wide-open space is exactly what some residents love—and what others find difficult.

CategoryDetails
County NameButte County
County SeatArco
EtymologyNamed after the Butte Mountains in the area. “Butte” refers to a steep hill with a flat top.
Cities, Towns, and CommunitiesArco, Butte City, Leslie, and more
Interstates and HighwaysU.S. Route 20, Idaho State Highway 33, Idaho State Highway 73
FIPS Code16-023
Total Area2,188 square miles (land: 2,178 sq mi; water: 10 sq mi)
Adjacent CountiesCuster County (Northwest), Lemhi County (Northwest), Clark County (Northeast), Jefferson County (East), Bingham County (Southeast), Blaine County (Southwest)
Time ZoneMountain Time Zone
StateIdaho
Coordinates43.6° N, 113.1° W
Major LandmarksCraters of the Moon National Monument, Atomic City, Butte City, Big Southern Butte
Population2,900
Scroll to Top