Trail Running calendar near Windsor 2025-2026

Diablo Trail Run takes place at Mount Diablo State Park, Mitchell Canyon Trailhead in Clayton, California. The event offers 4-mile, 10-mile, half marathon, marathon, 50K, and a Kids’ Run (50-yard dash). The 4-mile course is relatively flat, while the longer distances traverse mountainous, scenic ter..

Garin Park XC Challenge 2025, held at Garin/Dry Creek Pioneer Regional Parks on Garin Avenue in Hayward, California, is a 5K cross-country race described as a tough yet scenic run along the Garin Park ridge. Now in its 21st year, the event is part of the Pacific Association of USA Track & Field Cros..

Berkeley Trail Adventure takes place in the East Bay’s Tilden Regional Park and Wildcat Canyon, Berkeley, CA. The race offers four distances: 10K, Half Marathon, 35K, and 50K, with elevation gains from about 1,050 to 6,800 feet. Most of the course runs on technical dirt trails and non-technical fire..

Rocky Ridge is a trail race set in the Las Trampas Wilderness near San Ramon, California. The event offers a half marathon, a 10K, and a 5K through rugged hills and scenic vistas. The course is demanding and not beginner-friendly, rewarding perseverance with trails and views few runners will see, fo..

The Dick Collins Firetrails will take place in Castro Valley from Saturday 27 September 2025 to Sunday 28 September 2025. You can run between 42 and 100 kilometers.

Pacifica Summit Run, staged at San Pedro Valley State Park in Pacifica, California, features 10K and half-marathon trail races hosted by Urban Coyote Racing. Runners enjoy postcard views of the Pacific Ocean coastline and plenty of switchbacks as they ascend the summit on the upper San Francisco Pen..

Celebration of Life - Trail Trek in Willits, California, is a community-focused trail running event through the Brooktrails area. It offers three options: a 5K-ish Trail Run/Walk, a Trail Half Marathon, and Par Course loops. Courses traverse mostly single- and double-track forest trails with some ma..

JP's Backyard Ultra/Hike is a grassroots ultramarathon and hike held at Skyline Wilderness Park in Napa, California. In its third year, the event features a 3.3-mile loop with 550+ feet of climbing through rocky and shaded trails. Runners and hikers may do 1 to 10 loops, starting together on the hou..

The Women's Headlands Half Marathon is a scenic 13.2-mile trail race held annually in the Marin Headlands near Mill Valley, California. Celebrating its third year in 2025, the event features a challenging course with nearly 2,000 feet of elevation gain, showcasing stunning singletrack trails, sweepi..

Reservoir Dogs Trail Run in Orinda, CA offers 10K, Half Marathon, and 35K distances with start and finish in the San Pablo Reservoir Recreation Area. The event is notable as the first trail race to completely circumnavigate Briones Reservoir on EBMUD trails, delivering rolling open fire roads, tree-..

Star City San Bruno Mountain Half Marathon & 5K, organized by the Excelsior Running Club, takes place in Brisbane, CA, on the San Bruno Mountain trails. The course is 93% on trail with about 2,400 feet of elevation gain, including a single-track downhill and sweeping views of the Pacific, Bay, and S..

The Women's Headlands Half Marathon is a trail running event held in the scenic Marin Headlands near Mill Valley, California. This race features a brand-new half marathon course that highlights the area's stunning singletrack trails, challenging climbs, and exhilarating descents, offering runners a..

Go Wild Marin offers a trail and wilderness navigation challenge in Corte Madera, California, with 2-hour and 4-hour options. Teams of 1 to 5 use a custom map to locate up to 24 checkpoints scattered along trails and wild areas of the Tiburon Peninsula. The event emphasizes exploration and navigatio..

Ruth Anderson Memorial Endurance Run is an ultramarathon held in San Francisco, California, circling Lake Merced. Runners complete a multi-lap course on a 4.475-mile paved bike path, with aid stations at the start/finish and each loop. The event features distances associated with a 50M designation,..

The Napa Lapa Trail Adventure is Inside Trail Racing’s first time-based run, held at Skyline Wilderness Park in Napa, California. The event offers 12-hour, 6-hour, and 3-hour divisions, where competitors cover as much distance as possible in the allotted time. Each loop is about 4.1 miles with aroun..

The John Lawson Tamalpa Challenge is a three-race cross-country event held at Miwok Meadows in China Camp State Park, San Rafael, California. Each 4.2-mile course follows rolling single-track trails with about a quarter-mile on asphalt, starting near the Miwok Meadows gate and finishing in the Miwok..

The California Fall Classic at Lake Sonoma offers two ultramarathon distances: 100K and 55K, run at Lake Sonoma near Healdsburg, California. The weekend features on-site camping, live music, and local food, wine, and beer, with proceeds supporting the Children of Vineyard Workers Scholarship Fund. R..

The California Fall Classic at Lake Sonoma offers challenging 100K and 55K ultramarathon races set in the scenic wine country of Lake Sonoma, California. Known for its relentless courses featuring miles of single-track trails with stunning lake views, the event takes place in the fall, providing coo..

Diablo Summit Stomp is a Brazen Racing trail event held at 1700 Castle Rock Road in Walnut Creek, California, starting near Castle Rock Park and venturing into Mount Diablo State Park toward the summit for the 30K. Runners can choose from 30K, half marathon, 10K, or 5K, all on dirt trails with some..

The Running Dead 5K Fun Run in Union City, California, is a Halloween-themed community race at Civic Center/City Hall (34009 Alvarado-Niles Road). It offers a 5K open to adults and a 5K Youth option for younger runners. The course follows the Alameda Creek Trail from City Hall and returns to the fin..