Scenic Ridge Above The San Andreas Fault
Bolinas Ridge lies between the San Andreas Fault to the west and Kent Lake and Samuel P. Taylor State Park. Consequently the views are spectacular, but so is the flora. This hike is a great introduction to the flora of the central California coast. Starting at the northern trailhead at Sir Francis Drake Blvd. and going south 11.2 miles 1,200' up along the top of the ridge to the southern trailhead at the Fairfax-Bolinas Road is a journey through time.
The northern trailhead at 350' at Sir Francis Drake Blvd. is in cattle country with grassy hills that are green in the winter/spring and golden in the summer/fall. There are also a lot of cattle, but it seems like the area isn't being grazed heavily. Hike south as the trail goes up a few hundred gradual feet to the top of the ridge to the junction with the Jewell Trail at 600'. The views really open up here as Barnabe Mountain in Samuel P. Taylor State Park, Inverness Ridge in Point Reyes National Seashore and Tomales Bay provide photo opportunities. The open grassland on the ridge is dotted with small groves of coast live oak and chaparral, but it's still very open. California poppies put on a good show in the spring. They're especially interesting in the late afternoon as they roll up for the night.
Central Marin is separated from the Pacific Ocean first by Inverness Ridge in Point Reyes then Bolinas Ridge. Both ridges along with Mount Tamalpais intercept much of the water vapor blowing in from the west. The Douglas firs and Coast redwoods grow tall here, and the grass stays green a lot longer here than it does in most of the Bay Area as well. The ridges may look like twins, but they share different geologic origins due to being on different sides of the San Andreas Fault.
The next stretch headed south is 3.8 miles to 1,310' and the Bay Area Ridge Connector Trail down to the Cronin Fish Viewing Area (parking restrictions: see Directions below). This is when the vegetation really changes as grassland changes to chaparral then a mixed deciduous forest. Douglas firs are already quite common by this point, and they grow in increasing numbers as the trail heads south. The trail travels through the Golden Gate National Recreation Area until this point before entering the Marin Municipal Water District lands around Lake Kent. The lake lies 900' below you to the east, but you'll be lucky to get anything beyond a few glimpses through the dense forest. Cattle are not allowed in the watershed for obvious reasons, and you'll step over quite a few of these reasons on the northern half.
Bolinas Ridge is composed of submarine sandstone that was scraped off of the eastern edge of the Pacific Plate as it subducts under the North American Plate. Inverness Ridge and Point Reyes are composed of very old geologic formations that migrated north from the Big Sur/Monterey area along the western side of the San Andreas Fault over the eons. Even the casual observer might observe that redwoods are quite common east of the fault, but nonexistent to the west. Indeed the mighty redwood cannot tolerate Point Reyes' soil, but thrives on top of Bolinas Ridge and through the bottoms of the Lagunitas Creek drainage.
The Randall Trail junction in the redwoods is another mile to the south. The forest is now deep and dark as the redwood forest catches moisture from fog rolling in from the coast. Douglas iris grows in colonies of a few dozen while ferns seem to occupy every other place that doesn't have a redwood. The next 1.6 miles is to the junction with the McCurdy Trail. Both McCurdy and Randall head 1,200' down to Hwy. 1. It's only 3.3 miles from here to the southern trailhead at the Bolinas-Fairfax Road. The first mile or so is still in the redwoods, but the large trees are gradually replaced by smaller specimens and maritime chaparral. This is a good place to see the rare Marin manzanita and Mason's ceonathus. There are few long distance views here because the chaparral grows to about 8' tall, but the low coastal clouds always put on a show.
The last 3/4 mile is back in a redwood forest to the southern trailhead at 1,500'.
Check out the Official Route and Triplogs.