I believe I climbed 10,563' Alto Diablo Peak as part of a backpack on the San Bernardino Mountain Ridge in June 1961. It is unnamed on some maps and is located along the ridge going east from San Bernardino Peak before the ridge takes a dogleg southeast to coninue on with Charlton Peak, Little Charlton, Jepson Peak, and Mount San Gorgonio, the highest point in Southern California. This peak is part of the "9 Peaks Challenge"
Alto Diablo Peak and others on the San Bernardino Mountain Ridge
Here is a narrative and nice pictures of one route to Alto Diablo Peak. Also here.
