thumb|300px|Santa Rita No. 1 rig, used in the discovery of the Big Lake Oil Field in 1923.
Reagan County is a county on the Edwards Plateau in the U.S. state of Texas. As of the 2020 census, its population was 3,385. The county seat is Big Lake. The county is named after John Henninger Reagan (1818–1905), who was the postmaster general of the Confederate States and also a U.S. senator, U.S. representative, and first chairman of the Railroad Commission of Texas.
History
The region was first inhabited by Paleo-Indian, Suma-Jumano, Kiowa and Comanche peoples. Captains Hernán Martín and Diego del Castillo explored the region in 1650. In 1684, Juan Domínguez de Mendoza and Nicolás López reported on local indigenous groups.
Butterfield Overland Mail, which operated from 1858 to 1861, crossed through the center of the county. In 1878, Camp Grierson's Spring was established as a subpost of Fort Concho and named in honor of Col. Benjamin H. Grierson.
In 1903, Reagan County was carved from Tom Green County and named for United States Senator John Henninger Reagan. Stiles, named after local rancher William G. Stiles, became the first county seat. The Kansas City, Mexico and Orient of Texas Railway was completed in 1911.
In 1923, oil was discovered at the Big Lake Oilfield in the Permian Basin. Big Lake Oilfield, located on University of Texas System land, opened the Permian Basin to oil production and endowed the Permanent University Fund. The rig was named Santa Rita #1 for The Patron Saint of the Impossible. Big Lake was incorporated as a city. In 1924, shortly after the oil boom, the town community of Best plunged into vice and violence, necessitating the intervention of the Texas Rangers. The Rangers destroyed buildings that were being used as brothels, gambling houses, and saloons. In 1925, the county seat was moved to Big Lake by a vote.
In 1951, there was a renewed oil boom from production in the Spraberry Trend. The Spraberry Trend, the third-largest oil field in the United States by remaining reserves, underlies much of the county.
Major highways
- 20px U.S. Highway 67
- 20px State Highway 137
- 20px Ranch to Market Road 33
Adjacent counties
- Glasscock County (north)
- Sterling County (northeast)
- Tom Green County (east)
- Irion County (east)
- Crockett County (south)
- Upton County (west)
- Midland County (northwest)