Formed February 2, 1865 (2nd county)
Beaverhead County (9,374), Dillon (3,880)
The Beaverhead County tan brick courthouse on a square at Pacific, Bannack, Court, and Atlantic streets was built in 1889. Atlantic Street is Interstate Highway 15 Business passing through the town. Sidney Smith is the designer of this Classical Revival building. The structure was enlarged in 1975. Dillon had an earlier courthouse from 1875. February 2, 1865 was when Beaverhead County came into being as the 2nd county. Bannock was the first county seat until 1875 when Dillon became the seat. The county gets its name from a rock in the Jefferson River. The county seat is named for railroad officer Sidney Dillon.
Beaverhead County government consists of a sheriff and 3 Commissioners. One District Court Judge serves Beaverhead, Jefferson, and Madison counties. The county is in the southwest part of the state on the border with Idaho. The Continental Divide forms its northwest and southern borders. Missoula, Montana is northwest and Billings, Montana is northeast of the county. The county center is 25.9 miles West of Dillon nearer Bannack. The county is surrounded clockwise by Deer Lodge, Silver Bow, and Madison counties and Idaho and Ravalli and Granite counties.
The area of the county is 5543 square miles. It is 1 out of 56 in the state. It ranks 23 out of 56 in population in the state. It has a density of 1.7 persons per square mile making it 37 out of 56 in the state. Beaverhead County has 43.6% of its population in its incorporated areas. Interstate Highway 15 crosses the county from north to south from Silver Bow County to Idaho. The county’s overall shape looks like a recliner chair. Although it doesn’t appear to be true, Dillon is located slightly east of center in the county. Dillon is the county seat and the largest city. It is 41.4% of the county population.
Dillon
Lima
