San Marcos, city, seat of Hays County, south central Texas, on the San Marcos River; incorporated as a city 1877. It is a distribution and manufacturing center. Products include aerospace engine components, electronic controls, and metal stampings. The city is the seat of Southwest Texas State University (1899). A water theme park is here. A Spanish settlement (1808-12) preceded the present community, settled in the 1840s. The city name was bestowed by Spanish explorers who reached this site on the feast day of St. Mark. Population 23,420 (1980); 28,743 (1990); 34,733 (2000).
