Johnson County, Wyoming: History
Johnson County was created on December 8, 1875, as Pease County from parts of Albany, Carbon and Sweetwater Counties. It was organized in 1881. The county was initially named for Dr. E. L. Pease of Uinta County. But, in 1879, the county was renamed Johnson, for E. P. Johnson, a Cheyenne attorney.
In 1888, Sheridan County was created from a portion of Johnson County. In 1890, Big Horn County was created from Johnson County along with land from Fremont County and Sheridan County.
From 1889 to 1893, Johnson County was the scene of the Johnson County War, where wealthy cattle ranchers seeking to control limited resources enlisted hired guns to fight smaller settlers and homesteaders.
In 1911, the boundaries of Johnson County and adjacent Crook, Natrona and Weston Counties were adjusted to run along federal land survey lines.