Montana Population By County in 2018

Updated on January 27, 2024.

Based on the US Census Vintage data estimates, in 2018, the population of Montana was 1,061,818. Among all Montana counties, Yellowstone[object Promise] had the highest population (160,118), followed by Missoula[object Promise] (118,959), and Gallatin[object Promise] (111,878). Petroleum[object Promise] was the least populated county (517).

Hover over or click on the counties in the map below to see the populations. The data can also be found in a table below. You can use the table to sort, filter, and explore the data further.

You can see similar information for other states and by state for the United States.

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Montana Population By County in 2018
Montana Population By County in 2018
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County Population % of State Population
Beaverhead 9413 0.89
Big Horn 13305 1.25
Blaine 6764 0.64
Broadwater 6043 0.57
Carbon 10654 1.00
Carter 1223 0.12
Cascade 81756 7.70
Chouteau 5759 0.54
Custer 11576 1.09
Daniels 1706 0.16
Dawson 8683 0.82
Deer Lodge 9159 0.86
Fallon 2925 0.28
Fergus 11088 1.04
Flathead 102100 9.62
Gallatin 111878 10.54
Garfield 1262 0.12
Glacier 13797 1.30
Golden Valley 825 0.08
Granite 3355 0.32
Hill 16351 1.54
Jefferson 12084 1.14
Judith Basin 1950 0.18
Lake 30346 2.86
Lewis and Clark 68775 6.48
Liberty 2440 0.23
Lincoln 19862 1.87
McCone 1655 0.16
Madison 8586 0.81
Meagher 1847 0.17
Mineral 4314 0.41
Missoula 118959 11.20
Musselshell 4623 0.44
Park 16662 1.57
Petroleum 517 0.05
Phillips 4047 0.38
Pondera 5936 0.56
Powder River 1729 0.16
Powell 6920 0.65
Prairie 1056 0.10
Ravalli 43377 4.09
Richland 10955 1.03
Roosevelt 11084 1.04
Rosebud 9047 0.85
Sanders 11744 1.11
Sheridan 3379 0.32
Silver Bow 34768 3.27
Stillwater 9496 0.89
Sweet Grass 3701 0.35
Teton 6121 0.58
Toole 4830 0.46
Treasure 667 0.06
Valley 7409 0.70
Wheatland 2163 0.20
Wibaux 1029 0.10
Yellowstone 160118 15.08