Trail Running calendar near SoMa 2025-2026

Autumn trail festival at Lake Chabot Marina in Castro Valley offering 100k, 50 mile and marathon distances through classic East Bay parkland. Expect challenging terrain, a friendly community vibe, and generous finisher swag for all distance..

Join the 39th Ruth Anderson Memorial Endurance Run in San Francisco on October 10, 2026. Run scenic loops around Lake Merced on a certified course with 50k and 50 mile options and aid stations for a memorable autumn ultramarathon.

Enjoy a scenic but hilly trail run at Huddart Park with distances from 3 mile to half marathon, plus a 6 hour challenge and youth dash. Stay for pancakes after the race and choose a virtual option for 5K, 10K or half marathon.