Flathead County, Montana
A county in Montana, ranked 4 of 56 by population.
CountyFIPS 30029
- Population
- 115,429
- +10,556 (+10.1%) since 2020
- Land area
- 5,087
- square miles. A further 3.2% of the total area is water
- Population density
- 22.7
- people per square mile, computed rather than published
- County seat
- Kalispell
- Seat of county government.
- Established
- 1893
- 132 years ago
- Largest city
- Kalispell city
- Population 31,851.
Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; Wikidata (CC0), Wikidata. Retrieved 30 August 2026.
Satellite view
Aerial imagery of Flathead County with its boundary drawn on top. A map shows you the shape; this shows you what is inside it, and which side of the line a place falls on.
Where Flathead County ranks
Position among the 56 counties of Montana, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.
| Measure | Value | In Montana | Nationally |
|---|---|---|---|
| Population | 115,429 | 4th of 56 | 559th of 3,144 |
| Land area | 5,087 sq mi | 3rd of 56 | 76th of 3,144 |
| Population density | 22.7 per sq mi | 6th of 56 | 2,136th of 3,144 |
| Median household income | $73,925 | 11th of 56 | 922nd of 3,143 |
Full data for Flathead County
| Measure | Value | Source and vintage |
|---|---|---|
| Population | 115,429 | Vintage 2025 Population Estimates |
| Population in 2020 | 104,873 | Vintage 2025 Population Estimates |
| 2020 estimates base? | 104,353 | Vintage 2025 Population Estimates |
| Land area | 5,087 sq mi | 2025 Gazetteer Files |
| Water area | 168.7 sq mi | 2025 Gazetteer Files |
| Total area | 5,256 sq mi | 2025 Gazetteer Files |
| Population density? | 22.7 per sq mi | Computed: Vintage 2025 estimates divided by 2025 Gazetteer land area |
| Median household income | $73,925 | American Community Survey 2020-2024 5-Year Estimates |
| Median home value | $535,500 | American Community Survey 2020-2024 5-Year Estimates |
| Median age | 42.2 | American Community Survey 2020-2024 5-Year Estimates |
| Households | 44,233 | American Community Survey 2020-2024 5-Year Estimates |
| Housing units | 51,680 | American Community Survey 2020-2024 5-Year Estimates |
Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026. Population density is computed here, not published: it divides the Vintage 2025 population estimate by the 2025 Gazetteer land area, which are two different Census products. Retrieved 30 August 2026.
How the population changed
The Census Bureau publishes the components behind an estimate, not just the total. For the year to July 2025:
- Births minus deaths
- +101
- 1,192 births, 1,091 deaths
- Net migration
- +967
- More people moved in than moved out.
Source: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026. Retrieved 30 August 2026.
The 9 areas bordering Flathead County
Ordered by the length of the border actually shared, which the Census Bureau publishes in its county adjacency file and which no other county reference presents.
| Bordering area | State | Shared border | Population |
|---|---|---|---|
| Lake County | Montana | 105 mi | 33,392 |
| Lincoln County | Montana | 104 mi | 22,328 |
| Glacier County | Montana | 97 mi | 13,463 |
| Lewis and Clark County | Montana | 37 mi | 75,331 |
| Sanders County | Montana | 35 mi | 14,062 |
| Pondera County | Montana | 32 mi | 6,072 |
| Teton County | Montana | 25 mi | 6,496 |
| Powell County | Montana | 15 mi | 7,157 |
| Missoula County | Montana | 7.8 mi | 123,513 |
Source: US Census Bureau, County Adjacency File, 2025 County Adjacency File, released 15 September 2025. Retrieved 30 August 2026.
All 56 counties of Montana
Open the interactive Montana county map, or jump straight to any of them.
- Beaverhead County
- Big Horn County
- Blaine County
- Broadwater County
- Carbon County
- Carter County
- Cascade County
- Chouteau County
- Custer County
- Daniels County
- Dawson County
- Deer Lodge County
- Fallon County
- Fergus County
- Flathead County
- Gallatin County
- Garfield County
- Glacier County
- Golden Valley County
- Granite County
- Hill County
- Jefferson County
- Judith Basin County
- Lake County
- Lewis and Clark County
- Liberty County
- Lincoln County
- Madison County
- McCone County
- Meagher County
- Mineral County
- Missoula County
- Musselshell County
- Park County
- Petroleum County
- Phillips County
- Pondera County
- Powder River County
- Powell County
- Prairie County
- Ravalli County
- Richland County
- Roosevelt County
- Rosebud County
- Sanders County
- Sheridan County
- Silver Bow County
- Stillwater County
- Sweet Grass County
- Teton County
- Toole County
- Treasure County
- Valley County
- Wheatland County
- Wibaux County
- Yellowstone County
Data on this page last rebuilt 30 August 2026. How these figures are produced.