Mt. Tam Trail Run

Mt. Tam Trail Run is held in Stinson Beach, California, on November 7, 2026, and is put on by Inside Trail. Four formats are offered on the trails of Mount Tamalpais: the 50K (31 miles) and 30K (18.6 miles) start at 7:30 AM, followed by the half marathon (13.1 miles) and the 10K at 8:00 AM.

Running from the coast up toward Mt. Tam means you should expect a lot of vertical whatever distance you choose, so hill training is the priority. The 10K and half marathon are good ways to discover Marin trail running, while the 30K is a strong intermediate step for runners who are not quite ready for a 50K. If you take on the 50K, plan on a 16-week build with long runs that include several thousand feet of climbing, and practice running downhill on tired legs since that is what will get you back to the beach in good shape.