The canyon later appeared on film: Tahquitz Falls provided a setting for a scene in Frank Capra’s 1937 Lost Horizon. This filming took place in a landscape of enduring importance to the Cahuilla. The canyon lies on the Agua Caliente Indian Reservation and is overseen by the Agua Caliente Band of Cahuilla Indians, which maintains its visitor center and hiking trail. Source: https://en.wikipedia.org/wiki/Tahquitz_Canyon
Source: Wikipedia, “Tahquitz Canyon”; Agua Caliente Band of Cahuilla Indians, official Tahquitz Canyon visitor information