Alta Loma is one of three formerly unincorporated areas that became part of the city of Rancho Cucamonga, California, United States in 1977. The community is located at 34°09′N 117°36′W / 34.15°N 117.60°W / 34.15; -117.60Coordinates: 34°09′N 117°36′W / 34.15°N…