Salvation Mountain is a hillside visionary environment created by local resident Leonard Knight (1931–2014) in the California Desert area of Imperial County, north of Calipatria, northeast of Niland, near the Slab City squatter/art commune, and several miles from the Salton Sea.

The artwork is made of adobe bricks, discarded tires and windows, automobile parts and thousands of gallons of paint. It encompasses numerous murals and areas painted with Christian sayings and Bible verses, though its philosophy was built around the Sinner's Prayer.

The Folk Art Society of America declared it "a folk art site worthy of preservation and protection" in the year 2000. In an address to the United States Congress on May 15, 2002, California Senator Barbara Boxer described it as "a unique and visionary sculpture... a national treasure... profoundly strange and beautifully accessible, and worthy of the international acclaim it receives".

In December 2011, the 80-year-old Knight was placed in a long-term care facility in El Cajon for dementia. Leonard Knight died on February 10, 2014, in El Cajon. He was able to visit Salvation Mountain for the last time in May 2013; the visit was recorded by KPBS (TV).

Concern was raised in 2012 for the future of the site, which requires constant upkeep due to the harsh desert environment. Many visitors were donating paint to the project, and a group of volunteers worked to protect and maintain the site. In February 2011, a public charity, Salvation Mountain, Inc., was established to support the project. In 2013, the Annenberg Foundation donated $32,000 to Salvation Mountain Inc. for materials and equipment to "improve security and strengthen operations". A 2014 article stated that Salvation Mountain Inc. was operated by the nine volunteer members of its board.