San Miguel Island is 14 square miles, and ranks sixth in size of the eight California Channel Islands. Including Prince Island which lies in the entrance to Cuyler's Harbor, San Miguel Island contains 9325 acres. It is approximately eight miles long and four miles wide, and is the westernmost of the Northern Channel Islands. San Miguel Island is approximately 26 miles from the mainland and its closest neighbor, Santa Rosa is 3 miles to the east. In 1980 San Miguel Island became one of the five islands included in the Channel Islands National Park.