Montana 2020 Census Total Voting-age Population (18yrs and over) By County

Updated on August 21, 2023.

According to the data from the US 2020 decennial Census, as at April 2020, the total Voting-age population (18 years and over) of Montana was 850,123, which was 78.41% of the total Montana population.

Yellowstone County had the highest voting-age population (126,567), followed by Gallatin County (95,459), and then Missoula County (95,035). On the other hand, the 3 counties with low voting-age population were: Petroleum County (413), Treasure County (581), and Golden Valley County (661).

You can also see this information for other states and also for the US by state.

Hover over or click on the counties to see the number and percentage of Montana population that lives in each county. 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 also see the voting-age population by county for the different racial groups as well as the different ethnicities in Montana.

Montana 2020 Census Total Voting-age Population By County
Montana 2020 Census Total Voting-age Population By County
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County Voting-age Population % of Montana Pop.
Beaverhead 7524 0.89
Big Horn 8747 1.03
Blaine 4965 0.58
Broadwater 5309 0.62
Carbon 8506 1.00
Carter 1088 0.13
Cascade 65587 7.72
Chouteau 4346 0.51
Custer 9247 1.09
Daniels 1311 0.15
Dawson 6974 0.82
Deer Lodge 7851 0.92
Fallon 2209 0.26
Fergus 9076 1.07
Flathead 81505 9.59
Gallatin 95459 11.23
Garfield 897 0.11
Glacier 9448 1.11
Golden Valley 661 0.08
Granite 2706 0.32
Hill 11997 1.41
Jefferson 9566 1.13
Judith Basin 1647 0.19
Lake 23912 2.81
Lewis and Clark 55685 6.55
Liberty 1492 0.18
Lincoln 16037 1.89
McCone 1353 0.16
Madison 7231 0.85
Meagher 1591 0.19
Mineral 3719 0.44
Missoula 95035 11.18
Musselshell 3820 0.45
Park 14273 1.68
Petroleum 413 0.05
Phillips 3235 0.38
Pondera 4459 0.53
Powder River 1379 0.16
Powell 5921 0.70
Prairie 883 0.10
Ravalli 35657 4.19
Richland 8679 1.02
Roosevelt 7460 0.88
Rosebud 6076 0.72
Sanders 10214 1.20
Sheridan 2786 0.33
Silver Bow 28121 3.31
Stillwater 7095 0.84
Sweet Grass 2923 0.34
Teton 4768 0.56
Toole 3971 0.47
Treasure 581 0.07
Valley 5821 0.69
Wheatland 1610 0.19
Wibaux 730 0.09
Yellowstone 126567 14.89