Canyon Lake is a wealthy gated community in Riverside County, California, United States. One of only five gated cities in California, Canyon Lake began as a master-planned community developed by Corona Land Company in 1968. The “City of Canyon Lake” was incorporated on December 1, 1990. It geographically spans 4.7 square miles (12 km). The Lake was originally formed in 1927 after Railroad Canyon Dam was built.