thumb|Buffalo on the range in Crook CountyCrook County is a county in the northeastern corner of the U.S. state of Wyoming. As of the 2020 United States census, the population was 7,181, making it the third-least populous county in Wyoming. Its county seat and largest city is Sundance. The county is located at the northwestern extreme of the Black Hills, which are its defining geographical feature.
History
Crook County was created by the legislature of the Wyoming Territory on December 8, 1875, from portions of Albany and Laramie Counties. It was organized in 1888.
Crook County was named for Brigadier General George Crook, an army commander during the Indian Wars. In 1890, Crook County lost territory when Weston County was created. Campbell County was formed with land ceded by Crook County in 1911.
Geography
According to the US Census Bureau, the county has a total area of , of which is land and (0.4%) is water. The lowest point in the state of Wyoming is located on the Belle Fourche River in Crook County, where it flows out of Wyoming and into South Dakota.
Devils Tower National Monument is located in the Bear Lodge Mountains in Crook County.
thumb|[[Devils Tower National Monument|Devils Tower]]
The Missouri Buttes, at the northwestern end of the Black Hills, are located in the county, 3.5 miles northwest of Devils Tower.
Major highways
- 20px Interstate 90
- 20px U.S. Highway 14
- 20px U.S. Highway 16
- 20px U.S. Highway 212
- 20px Wyoming Highway 24
- 20px Wyoming Highway 51
- 20px Wyoming Highway 111
- 20px Wyoming Highway 112
- 20px Wyoming Highway 113
- 20px Wyoming Highway 116
- 20px Wyoming Highway 585
Adjacent counties
- Butte County, South Dakota – northeast
- Lawrence County, South Dakota – east
- Weston County – south
- Campbell County – west
- Powder River County, Montana – northwest
- Carter County, Montana – north
National protected areas
- Black Hills National Forest (part)
- Devils Tower National Monument
- Thunder Basin National Grassland (part)