Jefferson County, Montana Cities (2026)

City
Rank
2026 Pop. ↓
2020 Pop.
Annual Change
Density (/mi²)
Area (mi²)
Type
Boulder11,3281,2051.76%1,1811 City
Whitehall21,1561,0082.21%1,6401 Town

Jefferson County Cities Summary

Largest City

Boulder is the largest city in Jefferson County, with a population of 1,328.

Smallest City

Whitehall is the smallest city in Jefferson County, with a population of 1,156.

10 Largest Cities

There are 2 cities in Jefferson County, Montana.

Location of Jefferson County