Hawk Hill: People, birds flock for views URBAN OUTINGS

Visitors to Hawk Hill in the Marin Headlands sit to enjoy the view of San Francisco, CA on Friday, October, 5, 2012. Visitors to Hawk Hill in the Marin Headlands sit to enjoy the view of San Francisco, CA on Friday, October, 5, 2012. Photo: Alejandra Bayardo, The Chronicle Photo: Alejandra Bayardo, The Chronicle Image 1 of / 3 Caption Close Hawk Hill: People, birds flock for views 1 / 3 Back to Gallery

At 920 feet, Hawk Hill in the Marin Headlands is the perfect place to see migrating raptors as they fly south in the fall. (Raptors prefer to fly over land rather than water, buoyed by warm land thermals that provide lift.) The birds funnel into the headlands before heading for the short distance over water between San Francisco Bay and the Pacific Ocean.

Hawk Hill also provides a perfect human perch that overlooks the Pacific Ocean, Golden Gate Bridge, San Francisco Bay and the Marin Headlands, offering spectacular views.

At noon on Saturdays and Sundays through October at the top of Hawk Hill, the Golden Gate Raptor Observatory presents a docent program - "Hawk Talk" - about the raptors and also a banding demonstration at 1 p.m. with a live hawk. Both programs would be canceled in case of rain or fog. You will also see volunteers with the GGRO tracking the migration by counting, banding and radio-tracking birds.

Make sure to bring your binoculars.

What you'll find

Right before Conzelman Road becomes one-way, you will find a white gate at the entrance to a path leading to the top of Hawk Hill. Walk through the gate for a short but steep ascent, or go through the adjacent tunnel for a gentler walk to the summit. The views are unsurpassed. You can see a close-up of the Golden Gate Bridge with the Bay Bridge and San Francisco behind it. Look the other way to see Point Bonita and Rodeo Beach. Coyote brush and some poison oak line the trail.

Those who have previously visited Hawk Hill will notice a dramatic change: Nonnative Monterey pine and cypress trees have been cut down to restore habitat for the endangered Mission Blue butterfly. The removal has changed a forest into a gentle grassland allowing the butterflies access to lupine.

At the top of the hill, walk along the remains of the artillery installation, which provide excellent viewing platforms. You will probably find several birders with binoculars. Even if you're not an experienced birder, this is a good time to try out your own. You may see hawks, turkey vultures, falcons, kites, kestrels and even (albeit rare) eagles.

Battery Construction 129

But what are the strange tunnels running in and out of the hillside? If you went through the tunnel to climb Hawk Hill (as opposed to the gate path), you entered part of Battery Construction 129. This World War II-era battery was never completed or named. (Construction 129 is only a project number.) Begun in 1942 and built into the hillside for camouflage, the battery was to be armed with two 16-inch guns, each gun with carriage weighing more than 1 million pounds and capable of firing a shell 27 miles. However, all work stopped in 1944. The reason: The battery would not be effective against air attacks.

Shortly after the first tunnel, you come upon another tunnel to your right. Enter to look down at a huge circular hole in the ground. This is where one of the guns was to be mounted. Another tunnel, just through that, leads you back out to Conzelman Road.

Getting there

By car from San Francisco, go over the Golden Gate Bridge and take the Alexander Avenue exit, getting in the left lane and following the signs that read "101 South, San Francisco." Turn left onto Alexander Avenue at the stop sign and then right onto Conzelman Road. At the traffic circle, make sure to stay on Conzelman, following the signs to Hawk Hill. (Don't get diverted onto McCullough Road.) Continue to the parking area just before Conzelman becomes one-way.

Coming from the north on Highway 101, take the second Sausalito exit (after the Waldo Tunnel). Stay to the left, turning left at the stop sign. Then turn right onto Conzelman Road. Continue on Conzelman, following signs to Hawk Hill.

By bus, the Muni No. 76 tours the Marin Headlands, running hourly on Sundays and also on New Year's Day, Memorial Day, July Fourth, Labor Day, Thanksgiving and Christmas. It stops at many of the Headlands' highlights, but some people just take it for the scenic ride. You can catch the No. 76 in downtown San Francisco or at the Golden Gate Bridge toll plaza. To get to Hawk Hill, get off at Conzelman Road and McCullough Road. Walk about 0.6 miles uphill on Conzelman to Hawk Hill. (For more information, go to www.sfmuni.org.)

By bike from San Francisco, take the newly reopened west sidewalk on the Golden Gate Bridge, which is open on weekends and weekdays after 3:30 p.m. Earlier on weekdays, ride on the east side pedestrian sidewalk. Only bicycles are allowed on the west sidewalk, which ends in a small parking lot near the bottom of Conzelman Drive. Take a left on Conzelman to ride up to Hawk Hill. Note: The ride on Conzelman is all uphill.

Urban Outings are presented by Greenbelt Alliance, the Bay Area's advocate for protecting open spaces and creating vibrant places. To suggest an Urban Outing, contact Gail Todd, tour leader for S.F. City Guides and author of "Lunchtime Walks in Downtown San Francisco." To find out more about Greenbelt Alliance's work, visit www.greenbelt.org.