The original brick lighthouse at Point Arena was completed and first lit in 1870. In 1871, the United States Congress granted eight thousand five hundred dollars for the construction of a first-class steam fog signal (Public Acts of the Forty-First Congress, Third Session). The 1906 San Francisco earthquake destoyed most out-buildings and severely damaged the the light's tower. During construction of the new lighthouse, the first-order Fresnel lens was placed on a temporary tower until a new one was completed in 1909. The new lighthouse was the first in the U.S. to have a steel reinforced concrete tower and stands at a height of 115 feet, with a focal plane of 155 feet above sea level. The lens has been inactive since the lighthouse was automated in 1977. The original fog signal building is now a museum.
