Dusk descends on the Point Bonita lighthouse. The structure, built in 1854, is perched on an eroding rocky outcropping of the Marin Headlands and accessible by a corroding suspension bridge that would cost more than $1 million to repair, according Paul Batlan, a realty specialist with the Golden Gate National Recreation Area.  (Luis Sinco / LAT)

John Cantwell, a ranger with the National Park Service, holds his hat as gusty winds buffet the lighthouse on Alcatraz Island in San Francisco Bay.  (Luis Sinco / LAT)

Alcatraz Island visitors view the dining hall of the former federal penitentiary that housed notorious criminals. The lighthouse at Alcatraz has never been open to the public, except for a three-hour special tour three years ago. Visitors waited in line for more than an hour, said Cantwell.  (Luis Sinco / LAT)

The streaked lights of traffic along Fisherman’s Wharf frame Alcatraz Island. The U.S. Park Service is considering taking over five Bay Area lighthouses from the U.S. Coast Guard, including the one on Alcatraz Island.  (Luis Sinco / LAT)

A seagull soars on the wind in front of the octagonal lighthouse on Alcatraz Island.  (Luis Sinco / LAT)

Fog looms over the Golden Gate Bridge as seen from Fort Baker near Sausalito. The northern end of the bridge is the site of a fog warning station at Lime Point.  (Luis Sinco / LAT)

Paul Batlan, a realty specialist with the National Park Service, looks around the dilapidated structure that once housed the fog warning station at Lime Point in San Francisco Bay.  (Luis Sinco / LAT)

The Point Bonita lighthouse is one of five lighthouses the National Park Service is considering taking over from the Coast Guard.  (Luis Sinco / LAT)

Pat Reischl, a facilities manager with the National Parks Service, walks around the Fresnel lens of the Point Bonita Lighthouse.  (Luis Sinco / LAT)

A signpost points the way to faraway places at the Point Montara lighthouse at the southern end of the Golden Gate National Recreation Area.  (Luis Sinco / LAT)

Reischl walks through a tunnel leading to the Point Bonita Lighthouse.  (Luis Sinco / LAT)