It lies along California State Route 79, adjacent to the San Jacinto campus of Mt.

[1] Potrero Creek exits Massacre Canyon and joins the San Jacinto River at Gilman Hot Springs, just above California State Route 79, with Potero Creek delivering a large amount of sediment that creates an alluvial fan as well as periodically contributing to the flooding of the roadway.

The settlement's elevation of 1,525 feet (465 m) above sea level was beneficial for the boxers who trained at the Massacre Canyon Inn in the 1970s.

[4] Circa 1973, the Gilman family owned 500 acres occupied by "a major hotel and golf club, called Massacre Canyon Inn, and a 27-hole golf course...several motel and apartment complexes and a number of homes that are leased, a large bathhouse, the Gilman family home and a U.S. post office building.

"[5] The Church of Scientology's Gold Base complex is located in Gilman Hot Springs, California 92583.