Austin Independent School District is a school district based in the city of Austin, Texas, United States. Established in 1881, the district serves most of the City of Austin, the City of Sunset Valley, the Village of San Leanna, and unincorporated areas in Travis County. The district operates 129 schools including 84 elementary schools, 18 middle schools, and 16 high schools. As of 2013 AISD covers 172.4 square miles of land within the City of Austin, making up 54.1% of the city's territory.