Trail Running calendar near San Mateo 2026-2027

Join Western Pacific 2026 at Quarry Lakes in Fremont for scenic half marathon, 10K and 5K routes along the Western Pacific and Alameda Creek trails. Mostly flat trails welcome runners, walkers and remote runners.

Trail races in the Marin Headlands near Mill Valley offering marathon, half marathon and 10K routes on single track and fire roads with views of the Golden Gate Bridge, San Francisco Bay and the Pacific Ocean. The field is limited to 400 pa..

Trail runs on Mount Diablo on April 4, 2026 offering 50K, half marathon, 10K and 5K distances with a portion of fees supporting Save Mount Diablo. The half marathon is included in the Brazen Ultra Half Series.

The Romancing the Island Half Marathon will take place in Belvedere Tiburon on Saturday 11 April 2026. You can run between 10 and 21 kilometers.

Challenge yourself on scenic Lake Chabot trails April 11, 2026 in Castro Valley with distances from 8K to 50K plus a free kids dash. Looped, well marked courses offer big climbs, frequent aid stations and finisher medals for all.

A four-distance trail event in Calistoga that follows single track and fire road into the Mount St. Helena area. Routes include technical sections, long aid stretches, drop bag service at Highway 29, and finisher medals and shirts.

Trail races in April 2026 at Del Valle Regional Park offering Half Marathon, 10K and 5K distances with electronic chip timing. Finisher medals and t shirts are provided and walkers and hikers are welcome.

Horseshoe Lake Trail Run features 5 mile to 50K options plus a free kids dash on scenic Skyline Ridge with Pacific views. Marked trails, stocked aid stations, and finisher medals make it a rewarding day for trail runners.

A community fundraiser at Spring Lake Regional Park on April 18, 2026 featuring a half marathon, 10K and 5K. The low-waste event donates a portion of proceeds to Trione-Annadel State Park and includes a medal, shirt and post-race snacks.

Join the No Foolin' Foot Race in San Carlos on April 18, 2026 with 1K kids, 5K, 10K and a new 15K route across Big Canyon, Eaton and Pulgas Ridge. Festival vibes, tech shirts, pro timing and proceeds help local trails.

Trail races through Huddart County Park and Purisima Creek Redwoods on April 18, 2026, offering 10K, half, 35K and 50K courses with chip timing and marked aid stations. The event is limited to 450 runners and is a cupless format.

Trail race on Mt Tamalpais with a Half Marathon and 10K on coastal ridge single-track and road, limited to 300 participants, with aid stations, course markings, and participant t-shirts.

A 62 mile trail ultramarathon in the Marin Headlands near Stinson Beach, CA, featuring over 11,000 feet of climbing, marked trails and staffed aid stations with medical crews. Entry is limited to 400 runners and a four person relay is offer..

Join Tails & Trails on May 3, 2026 for a fun charitable run and walk supporting Dogwood Animal Rescue. Choose the in person 5K Dogwood Dash or a virtual any distance and help animals while you enjoy the outdoors in Windsor, CA.

A trail run on Pacific Union College trails in Angwin, CA on May 3, 2026 offering a 1 Mile Kids Run for ages 7 to 12, plus 10K and 26K distances. The event is cupless and proceeds benefit PUC Athletics.

Trail races from Stinson Beach into Muir Woods include a marathon, half marathon and a 7 mile course. Routes use the Dipsea Trail and Steep Ravine with ladders and stair sections, feature multiple aid stations, and are limited to 300 partic..

Run Berkeley's scenic trails at the Grizzly Peak Trail Run in Tilden Regional Park, with distances from a free kids 50 yard dash up to a challenging 50K. Expect rugged singletrack, stocked aid stations, finisher medals and awards for top ru..

Multi course trail run around Palo Corona Regional Park supporting Big Sur Land Trust. Options range from a 1 mile fun run to 5k, 12k, 25k and 35k+ courses across conserved lands.

Trail races on May 9, 2026 at Almaden Quicksilver County Park near San Jose, offering 50K and 100K on scenic single-track and fire roads. The 100K is a Western States qualifier and half the proceeds support local non-profits.

Join the Wine Half Marathon in Napa Valley on May 9, 2026, a 13.1 mile route through vineyards from Rutherford to Yountville. Founded by four French American wine professionals, the race blends warm hospitality, surprises, and scenic trails..