Point Bonita Lighthouse - Marin Headlands, CA
Posted by: 
DougK
N 37° 48.934 W 122° 31.776
10S E 541403 N 4185456
Point Bonita Lighthouse has been in operation since 1855.
Waymark Code: WM69H2
Location: California, United States
Date Posted: 04/28/2009
Views: 17
Point Bonita is located at the northern entrance to the San Francisco Bay. It is a rugged, steep peninsula jutting into the Pacific Ocean.
Point Bonita Lighthouse was first established in 1855 on a hill above the current location. In 1877, due to frequently foggy conditions, the light was moved to its present lower location, about 90 feet above sea level. Now the beam is consistently more visible up to 18 miles offshore.
The lighthouse sits on a solid base of volcanic basalt, surrounded by less durable types of rocks. This basalt was formed on the ocean bottom 200 million years ago. The rocks rounded forms, called "pillow basalt", are indicative of its ocean floor formation. In 1937 a rock slide destroyed the footpath leading to the lighthouse. A wooden causeway was built to bridge the gap until the early 1950's, when a suspension bridge was built to provide access to the lighthouse.
By 1979, Point Bonita was the last manned lighthouse in California. The light was automated shortly afterwards. The station, while still maintained by the Coast Guard, was handed over to the National Parks Service as part of the Golden Gate National Recreational Area.
The trail to the lighthouse is about a half a mile and includes a change in elevation of 120 feet down to the lighthouse. The trail is steep and often windy. It travels through a tunnel in the rock cut out by hand. The door to this tunnel is currently open Sat-Mon from 12:30PM to 3:30PM. There are docent-led hikes from the parking lot to the lighthouse.