The route to the summit of Mt Tamalpais (2,571ft) is about as straight forward as it gets, you simply hike up an old fire road to the top. The best comparison I could think of is an easier version of Mt Ord (via Slate Creek) in Arizona. The biggest difference is being able to see Pacific Ocean from Mt Tam!
The hike begins across the street from the Pantoll Ranger Station on the Old Stage Road and travels approximately 0.5 miles on asphalt before turning into gravel for the next three miles. The grade is gentle, only gaining 1,162 feet over four miles, and the view is spectacular on a clear day. At approximately two miles into the climb, there is a Cabin (West Point Inn) that has water, picnic tables, snacks for sale and one of the most relaxing places to stop for lunch on a hike (or bike) you could imagine! From the inn the trail turns into the Old Railroad Grade Fire Road for 1.5 miles before reaching the main paved road to the upper parking lot, visitor's center and bathrooms just shy of the peak. This section is a little more challenging and you'll begin to encounter several trails crossing the mountain, simply continue going up, it's very apparent where to go by now. To the immediate left of the bathrooms there is a railroad-tie path leading to the peak, follow this for the remaining 0.3 miles and you will arrive at your destination; Mt Tamalpais Summit!
Check out the Official Route and Triplog.
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.