Beaumont is a city in Riverside County, California, United States, located at the summit of the San Gorgonio Pass, between the San Bernardin…Beaumont is a city in Riverside County, California, United States, located at the summit of the San Gorgonio Pass, between the San Bernardino Mountains and Mount San Gorgonio to the north, and the San Jacinto Mountains and San Jacinto Peak to the south.