Since the late 1800s, the island — a former military installation, quarantine station and immigrant processing and detention site — has had three navigational aids. There was a fog bell station with its own keeper on Point Knox, a promontory on the island’s southwest corner; and small lighthouses on Point Stuart (on the western end) and Point Blunt (on the east side).
After your ferry ride from Tiburon or San Francisco, walk past the park visitor center and up the hill to the paved Perimeter Road. Head to the red, abandoned Camp Reynolds hospital and, to the right of it, pick up the Point Stuart Loop, a narrow earthen path that will lead you to a point on the island’s edge. (Watch out for poison oak!) The unmarked Point Stuart Lighthouse, which clings precariously to the edge of the island below the trail, is off-limits and blocked off by a chain-link fence. But if you’re lucky, you can catch a glimpse of its red roof through the fence.
Get back on Perimeter Road and go south to the well-marked concrete remains of the military’s Battery Ledyard. Take a short but steep path down to those ruins and, from there, look at the rocky point below (which is not accessible by foot). Somewhat embarrassingly, I shouted, “Yeah!” when I saw what was still down at the ocean’s edge: the 3,000-pound bronze fog bell installed in 1886.
In July 1906, the wind-up clockwork mechanism that struck that bell malfunctioned as a dense fog rolled in, just three months after the San Francisco earthquake that killed 3,000 people and destroyed much of the city. Ships had been pouring in as the city rebuilt. The female lighthouse keeper, Juliet Fish Nichols, alone in the fog bell station, struck the bell by hand for a grueling 20 hours and 35 minutes at the same rate as the automated mechanism — twice every 15 seconds — until the weather cleared.
After marveling at the bell, take Perimeter Road east toward Point Blunt. From the road, you can plainly see the automated green flash of the Point Blunt Lighthouse, which is operated by the U.S. Coast Guard and off limits to the public.
The loop took me three hours, with stops. Cellphone service is surprisingly great, and I used Google Maps to help find the lighthouses. The welcome center was closed when I visited, but I got three well-earned stamps for my U.S. Lighthouse Society passport from the bike rental stand.