This trail is a great tour of the mountain’s ecology and geology, even on a foggy or hazy day when views are limited. The vegetation type is chaparral, dominated by hardy shrubs like manzanita and sturdy trees like madrone and oak. In spring you’ll see wildflowers like the blue lupines and yellow monkey flowers. You’ll notice many rocks along the trail are greenish in color, meaning they contain serpentine, a certain kind of metamorphic rock. The unique configuration of serpentine that occurs on Tamalpais is the state rock of California.

On a clear day, views stretch over green rolling hills all around, blue reservoirs to the northwest, the Pacific Ocean to the south, San Francisco Bay, and the city skyline to the east. The trail leads to the mountain’s summit, where a historic fire lookout stands. The tower is still staffed in order to spot fires and is not open to the public, but you’ll get quite a commanding view from its base.

Sources: http://www.friendsofmttam.org/wp-content/uploads/Plank-Walk-Brochure2015-05-01.pdf http://www.friendsofmttam.org/park/facts.html https://www.parks.ca.gov/pages/471/files/MountTamalpaisSPFinalWebLayout110816.pdf