Horsethief Canyon
Appearance
Horsethief Canyon, is a canyon, the upper part of Summit Valley in San Bernardino County, California. Its mouth is at an elevation of 3,123 feet / 952 meters. Its head lies at 34°19′33″N 117°25′38″W / 34.32583°N 117.42722°W at an elevation of 3,800 feet just east of the summit of Cajon Pass.[1] California State Routes 138 and 173 pass through the canyon.