Data / Rankings / Population density / Counties in Montana

Counties in Montana by population density

Yellowstone County had the highest population density of 56 counties in 2021, at 24.6 inhabitants per km². Garfield County had the lowest, at 0.1 inhabitants per km². The median was 1 inhabitants per km² and the figure for Montana was 2.9 inhabitants per km². Source: the U.S. Census Bureau.

Highest24.6Yellowstone County
Lowest0.1Garfield County
Median156 counties
Montana2.9History

All counties, 2021

CSVChart (SVG)

Yellowstone CountyYellowstone County: 24.6 inhabitants per km²24.6Silver Bow CountySilver Bow County: 19.1 inhabitants per km²19.1Gallatin CountyGallatin County: 18.2 inhabitants per km²18.2Missoula CountyMissoula County: 17.8 inhabitants per km²17.8Cascade CountyCascade County: 12.1 inhabitants per km²12.1Lake CountyLake County: 8.3 inhabitants per km²8.3Flathead CountyFlathead County: 8.3 inhabitants per km²8.3Lewis and Clark CountyLewis and Clark County: 8.1 inhabitants per km²8.1Ravalli CountyRavalli County: 7.4 inhabitants per km²7.4Deer Lodge CountyDeer Lodge County: 5 inhabitants per km²5Jefferson CountyJefferson County: 2.9 inhabitants per km²2.9Park CountyPark County: 2.4 inhabitants per km²2.4Broadwater CountyBroadwater County: 2.4 inhabitants per km²2.4Lincoln CountyLincoln County: 2.2 inhabitants per km²2.2Hill CountyHill County: 2.2 inhabitants per km²2.2Richland CountyRichland County: 2.1 inhabitants per km²2.1Carbon CountyCarbon County: 2.1 inhabitants per km²2.1Stillwater CountyStillwater County: 1.9 inhabitants per km²1.9Sanders CountySanders County: 1.8 inhabitants per km²1.8Roosevelt CountyRoosevelt County: 1.8 inhabitants per km²1.8Glacier CountyGlacier County: 1.8 inhabitants per km²1.8Mineral CountyMineral County: 1.5 inhabitants per km²1.5Dawson CountyDawson County: 1.4 inhabitants per km²1.4Pondera CountyPondera County: 1.4 inhabitants per km²1.4Custer CountyCuster County: 1.2 inhabitants per km²1.2Powell CountyPowell County: 1.2 inhabitants per km²1.2Teton CountyTeton County: 1.1 inhabitants per km²1.1Fergus CountyFergus County: 1 inhabitants per km²1Musselshell CountyMusselshell County: 1 inhabitants per km²1Toole CountyToole County: 1 inhabitants per km²1Big Horn CountyBig Horn County: 1 inhabitants per km²1Madison CountyMadison County: 1 inhabitants per km²1Sheridan CountySheridan County: 0.8 inhabitants per km²0.8Sweet Grass CountySweet Grass County: 0.8 inhabitants per km²0.8Granite CountyGranite County: 0.8 inhabitants per km²0.8Fallon CountyFallon County: 0.7 inhabitants per km²0.7Beaverhead CountyBeaverhead County: 0.7 inhabitants per km²0.7Blaine CountyBlaine County: 0.6 inhabitants per km²0.6Rosebud CountyRosebud County: 0.6 inhabitants per km²0.6Valley CountyValley County: 0.6 inhabitants per km²0.6Chouteau CountyChouteau County: 0.6 inhabitants per km²0.6Wheatland CountyWheatland County: 0.6 inhabitants per km²0.6Liberty CountyLiberty County: 0.5 inhabitants per km²0.5Daniels CountyDaniels County: 0.5 inhabitants per km²0.5Judith Basin CountyJudith Basin County: 0.4 inhabitants per km²0.4Wibaux CountyWibaux County: 0.4 inhabitants per km²0.4Meagher CountyMeagher County: 0.3 inhabitants per km²0.3Phillips CountyPhillips County: 0.3 inhabitants per km²0.3Treasure CountyTreasure County: 0.3 inhabitants per km²0.3Golden Valley CountyGolden Valley County: 0.3 inhabitants per km²0.3McCone CountyMcCone County: 0.3 inhabitants per km²0.3Prairie CountyPrairie County: 0.2 inhabitants per km²0.2Powder River CountyPowder River County: 0.2 inhabitants per km²0.2Carter CountyCarter County: 0.2 inhabitants per km²0.2Petroleum CountyPetroleum County: 0.1 inhabitants per km²0.1Garfield CountyGarfield County: 0.1 inhabitants per km²0.1
inhabitants per km². Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-09.

Full ranking

RankCounties2021
inhabitants per km²		Change on 2020
1Yellowstone County24.6+1.4%
2Silver Bow County19.1+0.8%
3Gallatin County18.2+2.9%
4Missoula County17.8+1.3%
5Cascade County12.1+0.2%
6Lake County8.3+2.6%
7Flathead County8.3+3.7%
8Lewis and Clark County8.1+1.9%
9Ravalli County7.4+3.7%
10Deer Lodge County5+1%
11Jefferson County2.9+2.7%
12Park County2.4+1.7%
13Broadwater County2.4+6.8%
14Lincoln County2.2+4.3%
15Hill County2.2-0.3%
16Richland County2.1-1.8%
17Carbon County2.1+3.7%
18Stillwater County1.9+0.3%
19Sanders County1.8+3.8%
20Roosevelt County1.8-0.1%
21Glacier County1.8-0.2%
22Mineral County1.5+6.5%
23Dawson County1.4-0.8%
24Pondera County1.4+2.4%
25Custer County1.2+0.9%
26Powell County1.2+1.1%
27Teton County1.1+0.4%
28Fergus County1+1.3%
29Musselshell County1+3.5%
30Toole County1+0.3%
31Big Horn County1-1.4%
32Madison County1+3.3%
33Sheridan County0.8+1.1%
34Sweet Grass County0.8+0.9%
35Granite County0.8+1.6%
36Fallon County0.7-0.6%
37Beaverhead County0.7+1.8%
38Blaine County0.6-0.2%
39Rosebud County0.6-2.8%
40Valley County0.60%
41Chouteau County0.6+0.3%
42Wheatland County0.6-1.4%
43Liberty County0.5-1.1%
44Daniels County0.5+0.9%
45Judith Basin County0.4+1%
46Wibaux County0.40%
47Meagher County0.3+2.3%
48Phillips County0.30%
49Treasure County0.3+1.7%
50Golden Valley County0.30%
51McCone County0.3-1.2%
52Prairie County0.2+0.4%
53Powder River County0.2+1%
54Carter County0.2+0.6%
55Petroleum County0.1+3.4%
56Garfield County0.1+3.1%

Other periods

About this ranking

Resident population divided by land area in km². World Bank figures use mid-year population and land area excluding inland water.

United States: Census Bureau population estimates for 1 July divided by land area (water excluded) from the latest Census Gazetteer files. US tables often give people per square mile; multiply persons per km² by 2.59 to compare.

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 resident population on 1 July divided by land area from the latest Census Gazetteer files, persons per km². https://www2.census.gov/programs-surveys/popest/datasets/2020-2025/. Retrieved 2026-10-09.

Use this data in your AI agent

Invokely serves this figure to AI assistants through MCP and to code through a REST API, with the source and citation attached. Ask your assistant:

Rank Counties in Montana by population density using official data, and cite the source.
rank_places {"indicator":"population_density","level":"province","within":"Montana","limit":10}
GET https://invokely.ai/api/v1/rank?indicator=population_density&level=province&within=Montana&limit=10

Connect Claude, ChatGPT or Cursor in one step. The trial answers 25 calls a day without an account.

Questions

Which county has the highest population density?

Yellowstone County, with 24.6 inhabitants per km² in 2021, according to the U.S. Census Bureau.

Which county has the lowest population density?

Garfield County, with 0.1 inhabitants per km² in 2021.

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 resident population on 1 July divided by land area from the latest Census Gazetteer files, persons per km². Retrieved 2026-10-09.

Population density: other rankings

Counties in Montana: more rankings