Stephens county, created in 1907 and named in honor of John Stephens, a congressman from Amarillo, Texas, who strongly supported Oklahoma's push for statehood, is located in southwestern Oklahoma with Duncan serving as the county seat.

Major waterways in the county include Lake Humphreys, Clear Creek Lake and Lake Fuqua in the north and Waurika Lake, which is shared with Jefferson County, in the southwestern portion of the county.

The major north-south highway is U.S. 81 which approximates the old Chisholm Trail used by cattlemen driving their herds to Kansas stockyards. The "On the Chisholm Trail" museum, located in Duncan, is dedicated to preserving artifacts of this historic pre-railroad era.

Post-1900 history shows county industry transitioning from ranching and farming to oil production with Duncan assuming the title of the "Buckle in the Oil Belt."

The county population on July 1, 1999, was 43,076, an increase of 777 over the 1990 census.