# Sheridan County, Montana

Sheridan County is a county in the U.S. state of Montana. As of the 2020 census, the population was 3,539. Its county seat is Plentywood. Its northern boundary is the Canada–United States border south of Saskatchewan.

## History

The Montana Legislature established Sheridan County in 1913 from portions of Dawson and Valley Counties. It was named for American Civil War General Philip Sheridan. In the 1920s and 1930s the county was a hotbed of communist organizing. The CPUSA managed to elect several town and county officials. At the 1932 presidential election the communist candidate William Z. Foster got 576 votes (22%). International changes in communist organizing strategies, especially the move towards the popular front, effectively ended communist presence in the area.

## Geography

According to the United States Census Bureau, the county has a total area of 1,706 square miles (4,420 km$^2$), of which 1,677 square miles (4,340 km$^2$) is land and 29 square miles (75 km$^2$) (1.7%) is water.

### Major highways

* Montana Highway 5
* Montana Highway 16

### Adjacent counties and rural municipalities

* Rural Municipality of Happy Valley, Saskatchewan – northwest
* Rural Municipality of Surprise Valley, Saskatchewan – north
* Rural Municipality of Lake Alma, Saskatchewan – northeast
* Daniels County – west
* Divide County, North Dakota – east
* Williams County, North Dakota – east
* Roosevelt County – south

### National protected area

* Medicine Lake National Wildlife Refuge (part)

## Demographics
### 2020 census

As of the 2020 census, there were 3,539 people living in the county.

### 2010 census

As of the 2010 census, there were 3,384 people, 1,587 households, and 944 families living in the county. The population density was 2.0 inhabitants per square mile (0.77/km$^2$). There were 2,089 housing units at an average density of 1.2 units per square mile (0.46 units/km$^2$). The racial makeup of the county was 95.4% white, 1.7% American Indian, 0.4% Asian, 0.2% black or African American, 0.3% from other races, and 2.0% from two or more races. Those of Hispanic or Latino origin made up 1.5% of the population. In terms of ancestry, 33.8% were Norwegian, 26.0% were German, 12.0% were Danish, 11.6% were Irish, 5.5% were Swedish, 5.3% were English, and 5.0% were American.
Of the 1,587 households, 21.3% had children under the age of 18 living with them, 49.5% were married couples living together, 5.7% had a female householder with no husband present, 40.5% were non-families, and 37.1% of all households were made up of individuals. The average household size was 2.08 and the average family size was 2.70. The median age was 50.3 years.
The median income for a household in the county was $39,578 and the median income for a family was $55,313. Males had a median income of $46,932 versus $22,107 for females. The per capita income for the county was $26,537. About 6.4% of families and 14.5% of the population were below the poverty line, including 8.8% of those under age 18 and 10.4% of those age 65 or over.

## Politics

Sheridan County voters have selected the Republican County candidate in 80% of the national elections since 1980.
Sheridan County had a strong Communist Party presence in the first half of the 20th century. In the 1932 presidential election, Communist candidate William Z. Foster received 18% of the vote in the county, his strongest performance nationwide.
United States presidential election results for Sheridan County, Montana :
| Year | Republican | Republican | Democratic | Democratic | Third party(ies) | Third party(ies) |
| Year | No. | % | No. | % | No. | % |
| 2024 | 1,321 | 69.09% | 509 | 26.62% | 82 | 4.29% |
| 2020 | 1,403 | 69.11% | 574 | 28.28% | 53 | 2.61% |
| 2016 | 1,241 | 67.63% | 477 | 25.99% | 117 | 6.38% |
| 2012 | 1,207 | 62.60% | 665 | 34.49% | 56 | 2.90% |
| 2008 | 987 | 49.20% | 953 | 47.51% | 66 | 3.29% |
| 2004 | 1,159 | 56.87% | 846 | 41.51% | 33 | 1.62% |
| 2000 | 1,176 | 59.85% | 702 | 35.73% | 87 | 4.43% |
| 1996 | 832 | 34.17% | 1,187 | 48.75% | 416 | 17.08% |
| 1992 | 795 | 29.85% | 1,077 | 40.44% | 791 | 29.70% |
| 1988 | 1,381 | 49.98% | 1,354 | 49.00% | 28 | 1.01% |
| 1984 | 1,774 | 61.62% | 1,087 | 37.76% | 18 | 0.63% |
| 1980 | 1,658 | 56.94% | 955 | 32.80% | 299 | 10.27% |
| 1976 | 1,114 | 41.05% | 1,560 | 57.48% | 40 | 1.47% |
| 1972 | 1,500 | 53.96% | 1,197 | 43.06% | 83 | 2.99% |
| 1968 | 1,180 | 45.81% | 1,275 | 49.50% | 121 | 4.70% |
| 1964 | 837 | 30.39% | 1,905 | 69.17% | 12 | 0.44% |
| 1960 | 1,196 | 43.43% | 1,549 | 56.25% | 9 | 0.33% |
| 1956 | 1,153 | 38.31% | 1,857 | 61.69% | 0 | 0.00% |
| 1952 | 1,339 | 49.39% | 1,347 | 49.69% | 25 | 0.92% |
| 1948 | 699 | 28.50% | 1,515 | 61.76% | 239 | 9.74% |
| 1944 | 791 | 31.04% | 1,713 | 67.23% | 44 | 1.73% |
| 1940 | 892 | 29.23% | 2,108 | 69.07% | 52 | 1.70% |
| 1936 | 513 | 16.19% | 2,503 | 79.01% | 152 | 4.80% |
| 1932 | 739 | 22.77% | 1,450 | 44.67% | 1,057 | 32.56% |
| 1928 | 1,624 | 54.66% | 1,190 | 40.05% | 157 | 5.28% |
| 1924 | 905 | 35.32% | 176 | 6.87% | 1,481 | 57.81% |
| 1920 | 1,335 | 53.46% | 610 | 24.43% | 552 | 22.11% |
| 1916 | 1,724 | 32.15% | 3,264 | 60.86% | 375 | 6.99% |

## Communities
### City

* Plentywood (county seat)

### Towns

* Medicine Lake
* Outlook
* Westby

### Unincorporated communities

* Coalridge
* Comertown
* Dagmar
* Raymond
* Reserve

### Former towns

* Dooley
* Archer

## Census-designated places

* Antelope
* Homestead
* Redstone
* Reserve