# Stillwater County, Montana

Stillwater County is a county in the U.S. state of Montana. As of the 2020 census, the population was 8,963. Its county seat is Columbus.

## Geography

According to the United States Census Bureau, the county has a total area of 1,805 square miles (4,670 km$^2$), of which 1,795 square miles (4,650 km$^2$) is land and 9.2 square miles (24 km$^2$) (0.5%) is water.

### Major highways

* Interstate 90
* U.S. Highway 10 (Former)
* Montana Highway 78

### Adjacent counties

* Golden Valley County - north
* Yellowstone County - east
* Carbon County - south
* Park County - southwest
* Sweet Grass County - west

### National protected areas

* Custer National Forest (part)
* Grass Lake National Wildlife Refuge
* Hailstone National Wildlife Refuge

## Demographics
### 2020 census

As of the 2020 census, there were 8,963 people living in the county.

### 2010 census

As of the 2010 census, there were 9,117 people, 3,796 households, and 2,657 families in the county. The population density was 5.1 inhabitants per square mile (2.0/km$^2$). There were 4,803 housing units at an average density of 2.7 units per square mile (1.0 units/km$^2$). The racial makeup of the county was 96.8% white, 0.8% American Indian, 0.3% Asian, 0.1% black or African American, 0.4% from other races, and 1.6% from two or more races. Those of Hispanic or Latino origin made up 2.3% of the population. In terms of ancestry, 34.7% were German, 14.1% were Irish, 14.0% were English, 10.8% were Norwegian, and 6.9% were American.
Of the 3,796 households, 28.9% had children under the age of 18 living with them, 60.6% were married couples living together, 6.0% had a female householder with no husband present, 30.0% were non-families, and 25.8% of all households were made up of individuals. The average household size was 2.37 and the average family size was 2.84. The median age was 45.7 years.
The median income for a household in the county was $57,227 and the median income for a family was $65,438. Males had a median income of $51,830 versus $26,909 for females. The per capita income for the county was $27,168. About 6.0% of families and 9.5% of the population were below the poverty line, including 17.9% of those under age 18 and 7.2% of those age 65 or over.

## Politics

Stillwater County is a heavily Republican county in presidential elections. It has not voted for a Democratic presidential candidate since Franklin D. Roosevelt in 1936.
United States presidential election results for Stillwater County, Montana :
| Year | Republican | Republican | Democratic | Democratic | Third party(ies) | Third party(ies) |
| Year | No. | % | No. | % | No. | % |
| 2024 | 4,699 | 79.56% | 1,056 | 17.88% | 151 | 2.56% |
| 2020 | 4,462 | 77.72% | 1,156 | 20.14% | 123 | 2.14% |
| 2016 | 3,661 | 75.13% | 908 | 18.63% | 304 | 6.24% |
| 2012 | 3,337 | 70.97% | 1,248 | 26.54% | 117 | 2.49% |
| 2008 | 2,991 | 64.09% | 1,512 | 32.40% | 164 | 3.51% |
| 2004 | 3,090 | 73.34% | 1,025 | 24.33% | 98 | 2.33% |
| 2000 | 2,765 | 70.57% | 925 | 23.61% | 228 | 5.82% |
| 1996 | 1,871 | 49.24% | 1,282 | 33.74% | 647 | 17.03% |
| 1992 | 1,390 | 38.19% | 1,178 | 32.36% | 1,072 | 29.45% |
| 1988 | 1,920 | 56.82% | 1,407 | 41.64% | 52 | 1.54% |
| 1984 | 2,118 | 65.01% | 1,100 | 33.76% | 40 | 1.23% |
| 1980 | 1,828 | 61.26% | 919 | 30.80% | 237 | 7.94% |
| 1976 | 1,446 | 54.88% | 1,143 | 43.38% | 46 | 1.75% |
| 1972 | 1,698 | 67.95% | 716 | 28.65% | 85 | 3.40% |
| 1968 | 1,347 | 61.20% | 676 | 30.71% | 178 | 8.09% |
| 1964 | 1,140 | 50.20% | 1,130 | 49.76% | 1 | 0.04% |
| 1960 | 1,455 | 58.41% | 1,036 | 41.59% | 0 | 0.00% |
| 1956 | 1,540 | 60.32% | 1,013 | 39.68% | 0 | 0.00% |
| 1952 | 1,689 | 67.02% | 816 | 32.38% | 15 | 0.60% |
| 1948 | 1,137 | 54.48% | 890 | 42.64% | 60 | 2.87% |
| 1944 | 1,201 | 56.07% | 934 | 43.60% | 7 | 0.33% |
| 1940 | 1,255 | 50.71% | 1,201 | 48.53% | 19 | 0.77% |
| 1936 | 1,034 | 42.69% | 1,292 | 53.34% | 96 | 3.96% |
| 1932 | 1,085 | 44.23% | 1,281 | 52.22% | 87 | 3.55% |
| 1928 | 1,687 | 70.06% | 711 | 29.53% | 10 | 0.42% |
| 1924 | 1,412 | 59.88% | 375 | 15.90% | 571 | 24.22% |
| 1920 | 1,721 | 70.50% | 664 | 27.20% | 56 | 2.29% |
| 1916 | 918 | 42.01% | 1,197 | 54.78% | 70 | 3.20% |

## Communities
### Town

* Columbus (county seat)

### Census-designated places

* Absarokee
* Fishtail
* Nye
* Park City
* Rapelje
* Reed Point

### Unincorporated communities

* Beehive
* Dean
* Meyers Creek (partial)
* Molt
* Reed Point

### Ghost towns

* Limestone
* Springtime
* Wheat Basin