Trail Running calendar near Castro Valley 2026-2027

Obstacle course weekend with races from 5 km to 50 km, held April 3 and 4 2027 at Modesto Reservoir Regional Park near Waterford CA.

Trail event in Walnut Creek on April 3, 2027 offering 50K, half marathon, 10K and 5K options with part of fees supporting Save Mount Diablo.

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.

Badger Cove is a running event in Livermore, CA on April 17, 2027 offering a half marathon, 10K, 5K and a hiker division. Registration opens January 1 and closes February 2 with fees varying by event.

Trail fundraiser on April 17, 2027 offering a Half Marathon, 10K and 5K with a hilly technical half and a cup free policy.

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.

Trail running in the Stinson Beach and Muir Woods area with marathon, half marathon and 7 mile options. The event is organized by Enviro Sports and is tentatively scheduled for May 2027.

A 13.1 mile point to point half marathon through Napa Valley vineyards, mostly on private winery roads, finishing in Yountville's Wine Village.

Trailquake in Saratoga on Mother's Day offers 5K, 10K, a half marathon and a hiker division on redwood and pine forest trails. Finishers receive custom medals and shirt options.

May 15, 2027 trail races at Skyline Wilderness Park in Napa offer 10K, 21K, 30K and 50K courses with substantial elevation gain and staffed aid stations. This is a cupless event so runners must carry their own hydration.

A trail ultramarathon in Napa Valley centered at Skyline Wilderness Park, offering a solo 50 mile course and a one-loop 25 mile option. Cupless aid stations, on-course fueling, limited crew access, and drop bag support.

A race day in El Sobrante with a half marathon, 10K, 5K and a hiker division through the hills of Wilcat Canyon; registration windows and fees vary by distance.

Mud Factor's Seriously Fun 5K mud and obstacle run returns to Mahon Ranch in Elk Grove on May 16, 2027, with adult and KIDZ family waves and required waivers for participants.

Run for Amma in Los Gatos on May 22, 2027 offers trail races of 50K, 30K and 10K with significant elevation gain; all registration proceeds go to a UCSF cancer research lab.

Two-day obstacle race weekend at Toro Park near Salinas with Sprint 5K, Super 10K, kids races and spectator options.

Beer City Half San Jose on May 29, 2027 at Almaden Lake Park pairs trail and park running with a beer festival. Events include a half marathon, 10k, 5k, a 1 mile Beer Stroll, the Beat the Beast beer mile, and beer tastings.

Trail races of 10K, half marathon, and marathon at Toro Park, Salinas on May 30, 2027, over rocky trails and dirt roads with summer temperatures around 16ºC and an average altitude of 520 meters.

A point to point 100 mile trail race in Berkeley with 18,000 ft of climb, a 33 hour limit, and a capped field of 300; a Western States qualifier and UTMB Index race.

A historic 7.4 mile trail race from Mill Valley to Stinson Beach, known for steep stairs, a unique handicapping start system, and a limited field of about 1,500 runners.