Mount Tamalpais, also known as “Mount Tam,” is a prominent mountain peak in Marin County, California, about 17 miles north of SF’s Golden Gate Bridge. The mountain is affectionately regarded as a symbol of Marin County, famous for its panoramic 360-degree views of the Bay Area.
While a clear day will give you a fantastic vantage point over the East Bay, Mount Diablo, the SF Bay, and even the Farallon Islands, a foggy day is quite the treat, too. Every summer, visitors try to catch a glimpse of Mount Tam’s “rolling fog” phenomenon, when the marine layer looks like a weightless, ethereal ocean cascading over the hills and valleys.
Summer rolling fog at Mount Tamalpais
Summer is famously peak fog season in the Bay Area, with a thick marine layer blanketing the entire region in June, July, and August. The fog forms offshore, where the cold Pacific Ocean keeps the air above it saturated with moisture. As inland valleys heat up during the afternoon, a pressure gradient forms, pulling the cool, moist air inland. The fog typically moves in around 3-4pm as the land begins to cool, and a layer of warmer air traps the cool marine layer close to the ground overnight and into the morning.
This results in seas and rivers of fog rolling over the hills and ridges of Marin County, a phenomenon that is breathtaking to witness from a vantage point like Mount Tamalpais, especially at sunset. Photographers and casual observers flock to Mount Tam’s 2,571-foot East Peak, which often stays just out of the fog bank to create a surreal, heavenly experience.
Visiting Mount Tam
Mount Tamalpais is encompassed by protected public lands, including Mount Tamalpais State Park, Muir Woods National Monument, the Marin Municipal Water District watershed, and parts of the Golden Gate National Recreation Area. The Coast Miwok people called Mount Tamalpais home for thousands of years, and the name “Tamalpais,” meaning “west hill,” comes from their language.
The area is well-suited for camping, wildlife watching, and hiking on over 200 miles of trails. Outdoor recreation enthusiasts have frequented these lands since the 1850s, traversing redwood valleys, creeks, waterfalls, and grasslands. Once such visitor, Pulitzer Prize-winning Beat poet and environmentalist Gary Snyder, called it “the guardian peak for the Bay and for the City.”
You can reach Mount Tamalpais via a quick 45-minute drive up Highway 101. Arrive early, especially on weekends, as parking fills up fast. There is a day-use fee of $8 per vehicle, and park hours are 7AM to sunset.