Greater San Antonio, officially designated San Antonio–New Braunfels, is an eight-county metropolitan area in the U.S. state of Texas defined by the Office of Management and Budget (OMB). The metropolitan area straddles South Texas and Central Texas and is on the southwestern corner of the Texas Triangle. The official 2020 U.S. census showed the metropolitan area's population at 2,558,143—up from a reported 1,711,103 in 2000—making it the 24th largest metropolitan area in the United States. Downtown Austin and Downtown San Antonio are approximately 80 miles (129 km) apart, and both fall along the Interstate 35 corridor. This combined metropolitan region of San Antonio–Austin has approximately 5.1 million people.