Point Bonita Lighthouse facts for kids

Quick facts for kids
Point Bonita Lighthouse

Point Bonita Lighthouse in 2018
Point Bonita Lighthouse Location in California
Location	San Francisco Bay California United States
Coordinates	37°48′56″N 122°31′46″W / 37.815614°N 122.529578°W / 37.815614; -122.529578
Year first constructed	1855 (first)
Year first lit	1877 (current)
Automated	1980
Foundation	masonry basement
Construction	brick and cement building
Tower shape	hexagonal tower with balcony and lantern on fog signal building
Markings / pattern	white tower, black lantern dome
Height	33 ft (10 m)
Focal height	124 ft (38 m)
Original lens	Second order Fresnel lens
Current lens	Second order Fresnel lens
Range	18 nautical miles (33 km; 21 mi)
Characteristic	Oc W 4s.
Fog signal	2 blasts every 30s
Admiralty number	G4052
ARLHS number	USA-618
USCG number	6-0370

Point Bonita Lighthouse is a lighthouse located at Point Bonita at the San Francisco Bay entrance in the Marin Headlands near Sausalito, California. Point Bonita was the last manned lighthouse on the California coast. It was added to the National Register of Historic Places in 1991.

History

More than 300 boats ran aground near the Golden Gate during the California Gold Rush years, requiring a lighthouse.

The original Point Bonita Lighthouse, a 56-foot (17 m) brick tower, was built in 1855 at 306 feet (93 m) above sea level with a second order Fresnel lens. This was too high. Unlike the East Coast of the United States, the West Coast has dense high fog, which leaves lower elevations clear. Since the original light was so high, it was often cloaked in fog and could not be seen from the sea. As a result, the lighthouse was moved to its current location at 124 feet (38 m) above sea level in 1877. To access the new site, a 118-foot (36 m) long tunnel was hand carved through hard rock.

The lighthouse had the first fog signal on the West Coast, in the form of a 24-pounder siege gun.

Up until 1940 the lighthouse could be reached by a trail, but erosion caused the trail to crumble into the sea. A wooden walkway was installed, but when that became treacherous a suspension bridge was built in 1954. This is the only lighthouse in the United States which can only be reached by a suspension bridge.

The suspension bridge underwent repairs in 1979 and again in 1991, but the metal components were not able to stand up to the sea spray. As a result, the suspension bridge to the light house was closed to public access on January 6, 2010. According to the Federal Highway Administration, the bridge, which was 56 years old, had started to rust. It was replaced by a new span which opened April 13, 2012.

The new bridge construction cost a little over $1 million. It is made of tropical hardwood with steel suspension cables and attachments.

The United States Coast Guard currently maintains the light and fog signal.

Public access

The lighthouse is accessible to the public during limited hours (12:30–3:30 p.m.) on Sundays and Mondays, as well as on ranger-led interpretive sunset hikes, which requires a sign-up. Access to the bridge is barred at other times by a metal door on the shore end of the tunnel.

Gallery

In popular media

On the television show Murder in the First the lighthouse was a setting at the end of the second-season episode "Schizofrenzy".

The lighthouse can be found in the video game Watch Dogs 2.

Images for kids

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