Actually, the Channel Islands off the coast of Southern California were never connected to the mainland. These islands, of which Santa Catalina Island is considered the great jewel, were formed millions of years ago. Enormous chunks of the Earth’s crust, known as tectonic plates, shifted against each other with great force and, over time, pushed the islands up to the surface from the floor of the Pacific Ocean. In geology-speak, Catalina is known as an island caused by "tectonic uplift."

Conservancy File Photo

Catalina Island was created by a force known as "tectonic uplift."