POPULATION: INFO: Riverside County is located east of the Evergreen Mountains and along the northern shore of the Moreno River, north. Builtmore is the largest city and county seat of Riverside County. Caprice, a suburb city, and Morenoville are also located in Riverside County. Aspenwood, far to the north, is the most isolated city in the county. The climate varies, but around Builtmore, the weather is mild, with warm summers. Winter can see some strong storms and snow. To the high north, the climate is more wet and cold, with heavy snow in the winters, and mild summers.