Location: San Diego County, California

The highest point in San Diego County was originally named "Agua Caliente", which is Spanish for "hot or warm water". There is also an adjoining Ca%ntilde;ada, Agua Caliente and an Agua Caliente Creek. The peak name was anglicized by homesteaders (ca.1910) to distinguish it from the Rancho Agua Caliente (1844) to the south which was also noted for its springs.

All hot springs were sacred to the Cauhilla Indians who considered them to be connected underground and populated by sacred creatures. They were also like an underground transportation system for the use of shamans.

The name of this mountain refers to the famous hot springs found by Father Juan Mariner of the San Diego Mission (1795)-first such to be discovered in California. Today known as "Warner's Hot Spring", they can discharge at a rate of 200,000 gallons per day and maintain a uniform temperature of 140 deg F. Named for Jonathan Trumbell Warner (1807-95), a Connecticut trapper and trader who immigrated with David E. Jackson, becoming a naturalized citizen (1831), and then a large landowner and trader (1840). The cut,-off he took to get here became known as "Warner's Pass". Warner served U.S. Consul Thomas Larkin as a confidential agent and supported the U.S. side in the Mexican American War. His home became a special stop on the immigrant trail. His route was the one used by Kit Carson carrying war news east and returning with General Kearney (1846). It was used by Colonel George Cooke who headed the Mormon Battalion that built the first wagon road to California (1847). It was also used by the Butterfield Stage (1858-61).

The summit contains the remains of an abandoned radio tower, and a still active fire lookout tower (1928-).

It is still known locally as either "The Lookout", or "Warner's Peak".

Name first appears on GLO State of California map (1907).

Peak was on the original 1946 HPS Peak List. Weldon Heald climbed this peak in 1940.