Interstate 37 (I-37) is a 143.0-mile (230.1 km) intrastate Interstate Highway located within the U.S. state of Texas. The highway was first designated in 1959 as a route between Corpus Christi and San Antonio. Construction in the urban areas of Corpus Christi and San Antonio began in the 1960s and the segments of the Interstate Highway in rural areas were completed by the 1980s.