Rankin became the county seat after a railroad reroute

Upton County was created in 1887 and organized in 1910, with Upland as its first county seat. In fall 1911, the Kansas City, Mexico and Orient Railway laid tracks through a new townsite called Rankin — named for rancher F.E. Rankin. Most people and businesses in Upland picked up and moved to the railroad town. Rankin officially became the county seat on March 20, 1921.

The big change came in 1926 when oil was discovered nearby. The Yates field and the McCamey field drew thousands of workers. Rankin served as a supply hub for the oil patch, and by 1930 the county population had grown from about 500 to nearly 6,000. The county is named for two Confederate officers, John C. Upton and William F. Upton, both of whom reached the rank of lieutenant colonel. Today the county seat remains Rankin, a small town in a large oil-producing county.