Mortars carved in bedrock record early use of Reserve land by Cahuilla Indians. Charcoal deposits and scattered artifacts suggest the benchland that now includes the Reserve was once a seasonal campsite used for harvesting and milling acorns. The Cahuilla people ranged from the desert (including Oasis de los Osos) to throughout the San Jacinto Mountains. Their paths form the basis for a network of hiking trails that now link the Reserves with the rest of Hall Canyon, including other canyons and high-country wilderness areas. Scientists likely used these trails while surveying the flora and fauna of the San Jacinto Mountains (1878-1908). During the same period, short-lived ventures were attempted in the area: logging, homesteading, a leaf-mulching industry and plans for a subdivision. In 1941, Harry and Grace James took over the property as a campsite for the Trailfinders. In 1950, they completed Lolomi Lodge, now a private residence. They moved the Trailfinders’ base from Altadena to Hall Canyon. In 1966, the Jameses sold their land to the University of California as a natural reserve. Support for and interest in the Reserve continue to come from alumni of the Trailfinders. The Trailfinders’ donations funded the construction of nearly all of the facilities, including the main housing facility, The Trailfinders Lodge, as well as three new cabins and a classroom, completed in 2012.