Devils Tower National Monument is located in Crook County.
There were 2,308 households out of which 32.30% had children under the age of 18 living with them, 62.30% were married couples living together, 5.40% had a female householder with no husband present, and 28.70% were non-families. 24.90% of all households were made up of individuals and 10.30% had someone living alone who was 65 years of age or older. The average household size was 2.51 and the average family size was 3.01.
In the county the population was spread out with 26.90% under the age of 18, 6.60% from 18 to 24, 24.60% from 25 to 44, 27.20% from 45 to 64, and 14.70% who were 65 years of age or older. The median age was 40 years. For every 100 females there were 102.40 males. For every 100 females age 18 and over, there were 101.80 males.
The median income for a household in the county was $35,601, and the median income for a family was $43,105. Males had a median income of $34,483 versus $18,967 for females, indicating a relatively high level of income inequality based on gender. The per capita income for the county was $17,379. About 7.8% of families and 9.10% of the population were below the poverty line, including 9.90% of those under age 18 and 11.80% of those age 65 or over.