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 in the foothills of the south face of the San Gabriel Mountain range, near Cucamonga Peak and Mount Baldy. It is located in the 91701 and 91737 zip codes. The latitude of Alta Loma is 34.122N. The longitude is -117.597W. Its lowest elevation is approximately 1,371 feet (418 m) and extends to about 3,000 feet (910 m).