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.