Biohazard Cleanup Near Williamson Sunset Valley, TX

Sunset Valley is a small independent city in Travis County that is an enclave, completely surrounded on all sides by the city of Austin, about five miles southwest of downtown.

Sunset Valley was developed in the early 1950s by brothers M.H. and Clarence Flournoy, who bought a large tract for a residential subdivision, and the wooded valley among rolling hills inspired the name Sunset Valley.

Sunset Valley voters approved incorporation by a 45–6 vote on September 13, 1954, and the Village of Sunset Valley was officially incorporated days later with Clinton Vilven as its first mayor.

Sunset Valley had just 683 residents at the 2020 census, down slightly from 749 in 2010, keeping it one of the smallest incorporated cities in the Austin area.

Sunset Valley had only 365 people and 146 households in the 2000 census, and its residents have repeatedly annexed and de-annexed tracts over the decades to fine-tune the city's borders.

The first recorded land transactions in the Sunset Valley area date back to 1835, when the land was still under Mexican jurisdiction and was granted in large leagues to Theodore Bissell and Thomas Anderson.

Sunset Valley did not build its first city hall until 1977 or establish its own police department until 1979, and since 1998 Austin has provided its firefighting services under an inter-local agreement.

Sunset Valley covers only about 1.4 square miles, and the U.S. Postal Service did not officially recognize it as a mail destination until 2001, nearly half a century after incorporation.