[2] The county is located at the northwestern extreme of the Black Hills, which are its defining geographical feature.

Devils Tower National Monument is located in the Bear Lodge Mountains in Crook County.

The Missouri Buttes, at the northwestern end of the Black Hills, are located in the county, 3.5 miles northwest of Devils Tower.

As of the 2000 United States Census,[9] of 2000, there were 5,887 people, 2,308 households, and 1,645 families in the county.

As of the 2010 United States Census, there were 7,083 people, 2,921 households, and 2,016 families in the county.

[10] In terms of ancestry, 38.8% were German, 16.5% were English, 14.5% were Irish, 9.5% were Swedish, and 3.8% were American.

The last Democratic candidate to carry the county was Franklin D. Roosevelt in 1932,[14] and indeed Roosevelt in the following election – when he lost to Alf Landon by six percentage points – constitutes the last Democrat to pass forty percent.

In the last 12 Presidential elections the Democratic candidate has consistently received less than 23.5% of the county's vote.

In the Wyoming Senate the county is represented by Republican Ogden Driskill since 2011.

[18] Media related to Crook County, Wyoming at Wikimedia Commons