It was early February, when Hoppy and California threw their diamond hitchers on two pack horses and started the long journey to the eastern slopes of towering Mount Diablo. They were headed for Sulphur Valley, a third of the way to Diablo's top, and there they were supposed to rendezvous with a party of army officers who had started from the other side. The party should have reached Diablo's summit and descended again by the time they got there, but they hadn't. Sulphur Valley was as desolate as ever, and completely deserted...