According to theUnited States Census Bureau, the county has a total area of 5,572 square miles (14,430 km2), of which 5,542 square miles (14,350 km2) is land and 30 square miles (78 km2) (0.3%) is water.[5] It is the largest county in Montana by area.Beaverhead impact structure is in the area.TheBig Hole River (formerly called Wisdom River) runs through the county.
As of the2020 census, the county had a population of 9,371.[12]
Of the residents, 19.7% were under the age of 18 and 24.1% were 65 years of age or older; the median age was 43.9 years. For every 100 females there were 102.0 males, and for every 100 females age 18 and over there were 101.1 males. 47.3% of residents lived in urban areas and 52.7% lived in rural areas.[13]
There were 4,108 households in the county, of which 22.9% had children under the age of 18 living with them and 23.8% had a female householder with no spouse or partner present. About 32.9% of all households were made up of individuals and 14.6% had someone living alone who was 65 years of age or older.[14]
There were 4,918 housing units, of which 16.5% were vacant. Among occupied housing units, 65.1% were owner-occupied and 34.9% were renter-occupied. The homeowner vacancy rate was 1.9% and the rental vacancy rate was 8.2%.[14]
As of the2010 census, there were 9,246 people, 4,014 households, and 2,383 families living in the county. The population density was 1.7 inhabitants per square mile (0.66/km2). There were 5,273 housing units at an average density of 1.0 per square mile (0.39/km2). The racial makeup of the county was 94.8% white, 1.4% American Indian, 0.4% Pacific islander, 0.4% Asian, 0.2% black or African American, 1.2% from other races, and 1.6% from two or more races. Those of Hispanic or Latino origin made up 3.7% of the population. In terms of ancestry, 26.5% wereGerman, 23.9% wereEnglish, 15.4% wereIrish, 7.9% wereNorwegian, 6.5% wereScottish, and 3.4% wereAmerican.
Of the 4,014 households, 23.8% had children under the age of 18 living with them, 49.9% were married couples living together, 6.4% had a female householder with no husband present, 40.6% were non-families, and 33.0% of all households were made up of individuals. The average household size was 2.19 and the average family size was 2.79. The median age was 42.0 years.
The median income for a household in the county was $38,264 and the median income for a family was $53,036. Males had a median income of $35,568 versus $27,314 for females. The per capita income for the county was $21,110. About 10.8% of families and 15.0% of the population were below thepoverty line, including 14.4% of those under age 18 and 6.0% of those age 65 or over.
Beaverhead County is one of the largest cattle and hay producing areas of Montana. Barrett's Minerals, one of the world's largest talc mines, calls Beaverhead County home.[15] In 2009, Barrett Hospital and Healthcare was the largest private employer in the county.
Thomas Savage (1915-2003) spent his childhood and teen years on his family's ranch in Beaverhead County. His experiences there informed his best known novels,The Power of the Dog andThe Sheep Queen[citation needed].