Missoula County, Montana

Missoula County is a county located in the State of Montana. As of the 2010 census, the population was 109,426, making it the second-most populous county in Montana. Its county seat and largest city is Missoula. The county was founded in 1860.

Missoula County comprises the Missoula, MT Metropolitan Statistical Area.

History

Missoula County, Washington Territory was incorporated in 1860. Missoula County encompassed present-day Missoula and Deer Lodge Counties, as well as a good portion of land north and south of present-day Missoula County. Hell Gate Town, the county seat, was located at the confluence of the Clark Fork and Bitterroot Rivers.

The area encompassing today's Missoula County officially became part of the United States as a result of Oregon Treaty of June 14, 1846. It was part of the Oregon Territory's Clark County, which replaced the District of Vancouver September 3, 1844. The territory was divided on March 2, 1853 with Clark County becoming part of the new Washington Territory. Clark County was divided the next year to create Skamania County, which a month later was divided to create Walla Walla County, which was further divided in 1858 to create Spokane County.