Trail Running calendar near Castro Valley 2026-2027

Runs along the bay at Coyote Hills Regional Park in Fremont include a half marathon, 10K and 5K on mostly flat courses with mixed surfaces and boardwalks through marsh areas. Walkers are welcome.

Experience the coastal beauty of the Marin Headlands at the Golden Gate Trail Run. Choose from distances ranging from a 50K trail race to a fun kids dash with views of the Golden Gate Bridge and San Francisco.

Mt. Umunhum Trail Conquest (Winter) is a multi-distance trail event at Almaden Quicksilver County Park offering races from a kids run to a 50K with marked out-and-back courses, multiple aid stations, and summit sections to Bald Mountain or..

Jed Smith Ultra Classic on February 6, 2027 is a USATF certified loop event on the American River Parkway offering 50 mile, 50 k, marathon, 30 k and half marathon distances with two aid stations and race day packet pick up.

Run or walk along the San Francisco Bay starting from the San Leandro Marina. Choose from half marathon, 10K, or 5K distances with professional timing and custom finisher medals for all participants.

Montara Mountain Trail Run on February 20, 2027 in San Pedro Valley Park offers distances from a free 50 yard kids dash to a 50K, with marked trails, cupless aid stations every 6 to 7 miles, and substantial elevation gain on many courses.

Trail races in Sanborn County Park on mostly single track, technical forest trails with multiple distances, significant elevation gain, marked courses, and full aid at key points.

Experience a trail run across the forest and hills of Angel Island with views of San Francisco and the Golden Gate. Choose from multiple race distances including a youth dash and enjoy a picnic at Ayala Cove.

A point to point half marathon to the summit area of Mt. Umunhum on March 8, 2025, covering about 13.35 miles with 4,767 feet of ascent, marked mainly by pink ribbons and supported by aid stations with toilets.

A three day trail running weekend in Marin County offering a point to point 100K plus single loop 50K and 28K that summit Loma Alta and Big Rock Ridge.

A multi-distance trail event on March 22, 2025 at Calero County Park in San Jose offering runs from a kids race to a 50K, single track and dirt-road courses, multiple aid stations, and per-distance time limits.

Multiple trail distances run through Redwood Regional Park on March 20, 2027 at Chabot Space & Science Center. Routes use East Ridge, West Ridge, Stream and Bridle trails and distances were measured with a Rolatape surveyor's wheel.

An hourly backyard ultra on Dry Creek Parkway near Sacramento where runners repeat a 4.16 mile loop until only one completes the most yards. Each loop must be finished within the hour and the last runner to complete a loop wins.

Western Pacific 2027 stages a half marathon, 10K and 5K on a mostly flat course at Quarry Lakes Regional Recreation Area in Fremont on March 27, 2027, with tiered registration and a remote runner option.

A spring trail race at Pueblo Day Use Area in Santa Teresa County Park on April 5, 2025 offering 5K, 10K, 10 Mile and a half marathon across marked, hilly trails with aid stations and a four hour half marathon limit.

A multi-distance Spartan obstacle race weekend at Stanislaus County Parks on Apr 3-4, 2027, featuring Sprint, Super, Beast, Ultra and kids races across technical trails, grasslands and hills with signature obstacles and team options.

A trail running event in Walnut Creek on April 3, 2027 offering 50K, half marathon, 10K, 5K and a remote option. Part of entry fees support Save Mount Diablo and its land conservation work.

A trail event at Skyline Ridge Open Space Preserve offering distances from a 50 yard kids dash to a 50K race. Routes run largely on the Bay Area Ridge Trail with ocean and Santa Cruz Mountains views.

A trail event at Lake Chabot Regional Park offering distances from a 50‑yard kids dash to a 50K ultramarathon. The looped course circles the Lake Chabot reservoir and surrounding hills with measured distances.

No Foolin' Foot Race in San Carlos on April 24, 2027 offers 15K, 10K, 5K and a 1K kids trail course across Big Canyon, Eaton and Pulgas Ridge, with proceeds supporting local open space trail maintenance.