Gallatin County
Also known as Gallatin County, Montana, Gallatin County, MT
county in Montana, United States
Key facts
- Country
- United States
- State
- Montana
- Named after
- Gallatin River ( Albert Gallatin )
- Seat
- Bozeman
- Largest city
- Bozeman
- Total
- 2,632 sq mi (6,820 km )
- Land
- 2,603 sq mi (6,740 km )
- Water
- 29 sq mi (75 km ) 1.1%
- Estimate 2025
- 128,740
- Density
- 45.70/sq mi (17.65/km )
- Time zone
- UTC−7 ( Mountain )
- Summer dst
- UTC−6 ( MDT )
- Congressional district
~9 min read
Article
Gallatin County is a county located in the U.S. state of Montana. With its county seat in Bozeman, it is the second-most populous county in Montana, with a population of 118,960 in the 2020 census.
The county's prominent geographical features are the Bridger Range in the north, and the Gallatin Range and Gallatin River in the south, named by Meriwether Lewis in 1805 for Albert Gallatin, the United States Treasury Secretary who formulated the Lewis and Clark Expedition.