Salt Flat is an unincorporated community in northeastern Hudspeth County, Texas, United States. It lies along the concurrent U.S. Routes 62 and 180 north of the CDP of Sierra Blanca, the county seat of Hudspeth County. Its elevation is 3,730 feet (1,137 m). Although Salt Flat is unincorporated, it has a post office, with the ZIP code of 79847. Headquarters of the nearby Guadalupe Mountains National Park use this ZIP Code although located closer to Pine Springs, which has no post office.