Outwash from very heavy rains on the eastern slopes of the Southern California Peninsular Ranges in September of 1976, caused by tropical storm "Kathleen," cut an almost vertical cliff on the north bank of the Yuha Pinto Wash, just north of the international border in Imperial Valley. Some 80 Paleolithic flaked stone tools and utilized flakes were discovered solidly in place just above the base of the cut, overlain by alluvial, aeolian, and riverine deposits over 21 m thick. Three specimens of bone were recovered: one in place and associated with the artifacts but fragmentary and not identifiable as human, and two surface finds at the base of the exposure that were identified as human bone, but which had been washed out by the flood and were not positively relatable to the artifact level. Time of deposition of the artifacts is considered to be more than 50,000 B.P. by some unknown amount, based on pedological and geomorphic observations and radiocarbon dating of related features.