Roof of Marin
This hike is a pretty bare-bones jaunt from Sir Francis Drake Blvd. to the top of 1,762' Pine Mountain. You start at the roadside parking area along San Geronimo Valley Drive, and turn south and uphill onto Redwood Canyon Drive. There's a signed trailhead on the left about 200 feet up from San Geronimo Valley Dr. You are now in a dense second-growth redwood forest, but the trail is easy to follow even though it's definitely dark in there. About 1/4 mile from the trailhead there's a fire road branching off to the right going straight uphill, and a bridge to the left. Cross the bridge and follow the trail as it curves to the right then also heads straight uphill.
This next section is pretty gnarly. You're in for an unrelenting climb of over 800 feet over 1.1 mile. This unnamed trail heads up the northeast corner of a ridge running east-west. The northern slopes are covered by a dense forest of second-growth redwoods, and has a majestic forest of Douglas fir on the southern portion. The trail basically follows the spine of the ridge to the top while a fire road runs parallel a few hundred yards to the south. The trail turns right (west) as it crests out on the top of the ridge before reaching the San Geronimo Ridge fire road after hiking 1.5 mile from your car. You've been hiking through the Gary P. Giacomini Open Space Preserve. The rest of the route to Pine Mountain is in the Marin County Watershed.
San Geronimo Ridge fire road comes from the west and turns south at the junction. Go left and head south as the route gently ascends another ridge towards Pine Mountain. The vegetation here is dramatically different from the dark forests you've traveled through to get here. The soil here is serpentine, and only a few plants flourish here. Scrub forests of Sargent cypress dominate whatever area isn't covered by whiteleaf manzanita. There are also a lot of wildflowers, but I haven't identified them. The stands of Sargent cypress are very dense and look impenetrable. The view also opens up on this stretch. The leafy town of Fairfax emerges to the east while sizable Bolinas Ridge dominates the south, and Barnabe Mountain looms to the northwest.
The San Geronimo Ridge fire road gently ascends a few hundred feet over the next 1.8 miles before a modest descent leads to the junction with the Pine Mountain fire road to the right. You'll pass 2 fire roads that head downhill to the left in this stretch. The Pine Mountain fire road immediately ascends as it heads west towards the summit, but mellows out as you get closer. The fire road never reaches the actual summit so you must take the small trail to the right that heads through dense brush that will probably scratch you. The summit has a nice flat rock amidst some low manzanita. The views are spectacular, and Kent Lake can be viewed from the western edge of the summit.
Don't forget to check for ticks!
WARNING! Hiking and outdoor related sports can be dangerous. Be responsible and prepare for the trip. Study the area you are entering and plan accordingly. Dress for the current and unexpected weather changes. Take plenty of water. Never go alone. Make an itinerary with your plan(s), route(s), destination(s) and expected return time. Give your itinerary to trusted family and/or friends.