| County: | Musselshell County |
| State: | Montana |
| Founded Date: | February 2 |
| Founded Year: | 1911[1] |
| Seat Wl: | Roundup |
| Largest City Wl: | Roundup |
| Area Footnotes: | [2] |
| Area Total Sq Mi: | 1871 |
| Area Land Sq Mi: | 1868 |
| Area Water Sq Mi: | 2.8 |
| Area Percentage: | 0.1 |
| Population As Of: | 2020 |
| Population Total: | 4730 |
| Pop Est As Of: | 2022 |
| Population Est: | 5197 |
| Population Density Sq Mi: | auto |
| Web: | https://musselshellcounty.org/ |
| Ex Image: | Musselshell County Courthouse July 2020.jpg |
| Ex Image Cap: | The Musselshell County Courthouse in Roundup |
| District: | 2nd |
| Time Zone: | Mountain |
| Footnotes: |
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Musselshell County is a county in south-central Montana. As of the 2020 census, the population was 4,730.[3] Its county seat is Roundup.[4]
Musselshell County was created in 1911 by Montana Governor Edwin L. Norris. The area was taken from Fergus, from Yellowstone, and Meagher counties. It was named for the Musselshell River which runs southwest–northeast through the county. That river had been thus named in 1805 by the Lewis and Clark Expedition, due to the abundance of freshwater mussels found along its banks. In 1915, a western portion of the county was partitioned off to form Golden Valley County, giving Musselshell County its present boundaries.
The county's northwestern area is rolling grasslands, which slope southeastward to the Musselshell River and the forested Bull Mountains in the southeast. The county has abundant natural resources of coal deposits, subterranean oil, and timbered slopes.[1]
According to the United States Census Bureau, the county has a total area of, of which is land and (0.1%) is water.[5]
In the fourteen national elections after its organization, Musselshell County voters selected Republican presidential candidates 50% of the time, and Democratic candidates 50% of the time. However, since the 1968 election, the Republican candidate has been selected in every election.
As of the 2020 census, there were 4,730 people living in the county.
As of the 2010 census, there were 4,538 people, 2,046 households, and 1,276 families in the county. The population density was . There were 2,654 housing units at an average density of 1.4/mi2. The racial makeup of the county was 96.1% white, 1.3% American Indian, 0.2% black or African American, 0.2% Asian, 0.2% from other races, and 1.9% from two or more races. Those of Hispanic or Latino origin made up 2.6% of the population. In terms of ancestry, 28.1% were German, 16.5% were English, 16.1% were Irish, 7.6% were Norwegian, and 7.0% were American.
Of the 2,046 households, 23.2% had children under the age of 18 living with them, 52.4% were married couples living together, 6.5% had a female householder with no husband present, 37.6% were non-families, and 33.5% of all households were made up of individuals. The average household size was 2.19 and the average family size was 2.78. The median age was 49.1 years.
The median income for a household in the county was $37,033 and the median income for a family was $47,860. Males had a median income of $33,182 versus $25,750 for females. The per capita income for the county was $20,875. About 14.1% of families and 17.8% of the population were below the poverty line, including 28.6% of those under age 18 and 9.6% of those age 65 or over.