Missoula County remains state’s 2nd most populous, but Gallatin, Flathead make gains

Missoula County added more than 8,100 residents over the past seven years, maintaining its place as Montana’s second most populous county, according to U.S. Census estimates released last week.

Yet while Missoula County grew at 7.4 percent from April 1, 2010 to July 1, 2017, Gallatin County’s population surged 20.4 percent by adding more than 18,000 new residents.

In fact, Bozeman holds the top spot among the nation’s largest-gaining micropolitan areas, joining Kalispell (third), Twin Falls (fourth) and Centralia, Washington (tenth) on the list.

While population figures within municipal boundaries weren’t included in the latest batch of data, last year’s census estimates placed the city of Missoula’s population at 72,362 residents. The city of Bozeman was listed at 41,761.

Overall, Montana ranked 38th in the nation by population growth and 17th nationally by percent.

From April 1, 2010 to July 1, 2017, the state added 61,000 new residents for an increase of 6.2 percent, though nearly 77 percent of those new residents landed in Missoula, Gallatin, Yellowstone and Flathead counties.

Outside Wyoming, which grew 2.8 percent, Montana’s population growth was the lowest in the region. Idaho grew at 9.5 percent, Washington at 10.1 percent and Oregon at 8.1 percent. Both North and South Dakota also grew faster, at 12.3 and 6.8 percent respectively.

Last year’s estimates suggested that only three Montana counties had a population of more than 100,000 residents. This year, however, that number grow to four, with Flathead County joining the list. It gained an estimated 9,072 residents since 2010, placing its estimated population at 100,000.

Broken down by county, Yellowstone County remained the state’s most populous with 158,980 residents, followed by Missoula County with 117,441 residents. Gallatin County now claims 107,810 residents and Flathead at 100,000.

By growth, however, Gallatin gained the most new residents at 18,297, followed by Yellowstone at 11,008, Flathead at 9,072 and Missoula at 8,142.

10 Most Populous Counties as of July 1, 2017

Yellowstone County: 158,980

Missoula County: 117,441

Gallatin County: 107,810

Flathead: 100,000

Cascade County: 81,854

Lewis and Clark: 67,773

Ravalli County: 42,563

Silver Bow County: 34,602

Lake County: 30,273

Lincoln County: 19,440