[3] The first settlement in Butte County occurred about four miles (6 km) south of the present town site of Arco in 1878.

[6] Settlement of Antelope, Martin and Island (now Moore) also occurred prior to 1890.

[8][9] Construction of a railroad from Blackfoot to Mackay resulted in relocation of the town of Arco to its present site in 1901.

Butte County is included in the Idaho Falls, ID Metropolitan Statistical Area.

The county was named for the volcanic buttes that rise from the desert plain;[11] the largest is Big Southern Butte, located in the southern part of the county.

[12] The southwestern portion of the county includes the visitor center at the Craters of the Moon National Monument and Preserve, which extends south and west into three other counties.

As of the census[18] of 2000, there were 2,899 people, 1,089 households, and 802 families living in the county.

23.60% of all households were made up of individuals, and 10.90% had someone living alone who was 65 years of age or older.

As of the 2010 United States Census, there were 2,891 people, 1,129 households, and 788 families living in the county.

[19] In terms of ancestry, 33.4% were English, 18.5% were German, 10.6% were American, 9.1% were Irish, 7.6% were Danish, and 7.2% were Scottish.

No Democratic Party candidate has won a quarter of the county's votes since Bill Clinton in 1996.