Data / Rankings / Population aged 65 and over / Counties in Montana

Counties in Montana by share of population aged 65 and over

Prairie County had the highest share of population aged 65 and over of 56 counties in 2020, at 33%. Glacier County had the lowest, at 13%. The median was 24.4% and the figure for Montana was 20%. Source: the U.S. Census Bureau.

Highest33Prairie County
Lowest13Glacier County
Median24.456 counties
Montana20History

All counties, 2020

CSVChart (SVG)

Prairie CountyPrairie County: 33 %33Petroleum CountyPetroleum County: 32.5 %32.5Sanders CountySanders County: 32.4 %32.4Lincoln CountyLincoln County: 30.5 %30.5Madison CountyMadison County: 30.3 %30.3Golden Valley CountyGolden Valley County: 29.8 %29.8Granite CountyGranite County: 28.9 %28.9Powder River CountyPowder River County: 28.8 %28.8Judith Basin CountyJudith Basin County: 28.6 %28.6Meagher CountyMeagher County: 28.3 %28.3Ravalli CountyRavalli County: 28.1 %28.1Mineral CountyMineral County: 28 %28Garfield CountyGarfield County: 27.4 %27.4Sweet Grass CountySweet Grass County: 27.2 %27.2Wibaux CountyWibaux County: 27.1 %27.1Musselshell CountyMusselshell County: 27.1 %27.1Treasure CountyTreasure County: 26.8 %26.8Carter CountyCarter County: 26.7 %26.7Fergus CountyFergus County: 26.3 %26.3Deer Lodge CountyDeer Lodge County: 25.9 %25.9Carbon CountyCarbon County: 25.8 %25.8Daniels CountyDaniels County: 25.6 %25.6Wheatland CountyWheatland County: 25.2 %25.2Sheridan CountySheridan County: 25 %25Stillwater CountyStillwater County: 24.7 %24.7Liberty CountyLiberty County: 24.6 %24.6Beaverhead CountyBeaverhead County: 24.5 %24.5McCone CountyMcCone County: 24.4 %24.4Lake CountyLake County: 24.3 %24.3Jefferson CountyJefferson County: 24.2 %24.2Teton CountyTeton County: 23.7 %23.7Phillips CountyPhillips County: 23.7 %23.7Park CountyPark County: 23.2 %23.2Valley CountyValley County: 23.1 %23.1Broadwater CountyBroadwater County: 22.8 %22.8Pondera CountyPondera County: 22.6 %22.6Powell CountyPowell County: 22 %22Flathead CountyFlathead County: 21.6 %21.6Chouteau CountyChouteau County: 21.5 %21.5Dawson CountyDawson County: 20.8 %20.8Silver Bow CountySilver Bow County: 20.7 %20.7Custer CountyCuster County: 20.6 %20.6Lewis and Clark CountyLewis and Clark County: 19.6 %19.6Cascade CountyCascade County: 19.2 %19.2Toole CountyToole County: 18.3 %18.3Fallon CountyFallon County: 18.2 %18.2Yellowstone CountyYellowstone County: 17.9 %17.9Missoula CountyMissoula County: 17.5 %17.5Rosebud CountyRosebud County: 17.4 %17.4Hill CountyHill County: 16.1 %16.1Blaine CountyBlaine County: 15.9 %15.9Richland CountyRichland County: 15.7 %15.7Roosevelt CountyRoosevelt County: 13.7 %13.7Big Horn CountyBig Horn County: 13.5 %13.5Gallatin CountyGallatin County: 13.3 %13.3Glacier CountyGlacier County: 13 %13
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-09.

Full ranking

RankCounties2020 (%)
1Prairie County33
2Petroleum County32.5
3Sanders County32.4
4Lincoln County30.5
5Madison County30.3
6Golden Valley County29.8
7Granite County28.9
8Powder River County28.8
9Judith Basin County28.6
10Meagher County28.3
11Ravalli County28.1
12Mineral County28
13Garfield County27.4
14Sweet Grass County27.2
15Wibaux County27.1
16Musselshell County27.1
17Treasure County26.8
18Carter County26.7
19Fergus County26.3
20Deer Lodge County25.9
21Carbon County25.8
22Daniels County25.6
23Wheatland County25.2
24Sheridan County25
25Stillwater County24.7
26Liberty County24.6
27Beaverhead County24.5
28McCone County24.4
29Lake County24.3
30Jefferson County24.2
31Teton County23.7
32Phillips County23.7
33Park County23.2
34Valley County23.1
35Broadwater County22.8
36Pondera County22.6
37Powell County22
38Flathead County21.6
39Chouteau County21.5
40Dawson County20.8
41Silver Bow County20.7
42Custer County20.6
43Lewis and Clark County19.6
44Cascade County19.2
45Toole County18.3
46Fallon County18.2
47Yellowstone County17.9
48Missoula County17.5
49Rosebud County17.4
50Hill County16.1
51Blaine County15.9
52Richland County15.7
53Roosevelt County13.7
54Big Horn County13.5
55Gallatin County13.3
56Glacier County13

Other periods

About this ranking

Residents aged 65 or over as a percentage of total population. Spain: 1 January, INE annual census. United States: 1 July, Census Bureau population estimates. World Bank figures for other countries and the World refer to mid-year.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.

How to cite

U.S. Census Bureau. Population Estimates Program, county population by age and sex (cc-est agesex): residents aged 65 and over as a percentage of the total, 1 July; states and the nation summed from counties. https://www2.census.gov/programs-surveys/popest/datasets/2020-2025/counties/asrh/cc-est2025-agesex-all.csv. Retrieved 2026-10-09.

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Rank Counties in Montana by share of population aged 65 and over using official data, and cite the source.
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Questions

Which county has the highest share of population aged 65 and over?

Prairie County, with 33% in 2020, according to the U.S. Census Bureau.

Which county has the lowest share of population aged 65 and over?

Glacier County, with 13% in 2020.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, Population Estimates Program, county population by age and sex (cc-est agesex): residents aged 65 and over as a percentage of the total, 1 July; states and the nation summed from counties. Retrieved 2026-10-09.

Population aged 65 and over: other rankings

Counties in Montana: more rankings