Trail Running calendar near Fairfield 2025-2026

FOURmidable is a challenging trail running event held in Auburn, California, set in the scenic Sierra Nevada foothills. The race offers multiple distances including a 50K, 35.5K, half marathon, and 13K, catering to a range of endurance levels. Participants experience rugged terrain and picturesque n..

Redtail Ridge at Lake Chabot Regional Park in Castro Valley, CA offers multiple distances: 5K, 10K, Half Marathon, 30K, and 50K. The course unfolds on a mix of moderately technical dirt trails and non-technical fire roads, with some paved sections, and features rolling hills that reward pacing and t..

The Lost Trail Half Marathon and 5K take place at Granite Beach, Folsom Lake State Recreation Area, offering runners scenic lake views and vibrant wildflowers along well-marked courses. The half marathon covers 13.1 miles, while the 5K is 3.1 miles. The event features five aid stations strategically..

The Montara Mountain Trail Run takes place on Saturday, February 21, 2026, at San Pedro Valley Park, 600 Oddstad Boulevard, Pacifica, CA 94044. The event offers the following distances: 10K Half Marathon 20 mi Marathon 50K Kid's Run (6yo & younger, 50 yd dash) - Free Pre-registered runners re..

The Salmon Falls 50K Endurance Run is a challenging trail race set in the scenic foothills of Sacramento, California. This ultra-distance event starts at the Magnolia Ranch Trail Head near Coloma and features a stunning course that traverses the Cronan Ranch area, ultimately finishing at Folsom Lake..

Zoom Angel Island is a trail running event on Angel Island, accessible via chartered ferries from Tiburon, California, offering spectacular views of Marin County and San Francisco. Distances include 5 miles, 10 miles, 15 miles, plus a Kids Run (free). The hilly course circles the island and climbs M..

Way Too Cool 50K, the iconic 36th annual ultramarathon held in Cool, California, offers a 50K trail race and an expanding 10-mile endurance option. Runners navigate rolling Northern California hills, creek crossings, and breathtaking scenery, making it a beloved tradition in the ultrarunning communi..

The Marin Ultra Challenge is Inside Trail Racing’s premier Marin County long-distance trail race, offering 50-mile and 50K options. The route starts at Rodeo Beach and loops through the Marin Headlands, Mt. Tamalpais, and Muir Woods, delivering coastal and inland vistas, varied terrain from exposed..

Rattlesnake Dick is a trail ultramarathon presented by North Fork Clothing, held in Cool, California at the Cool Staging Area (7200 Saint Florian Court). The event offers three distances: 50K, 25K, and 10K, all with generous 10-hour cut-offs and back-of-the-pack friendly courses. Runners ascend and..

2026 Napa Valley Trail Marathon, Half Marathon & 10K takes place at Bothe-Napa Valley State Park in Saint Helena, California. The event offers three trail distances: marathon, half marathon, and 10K. Runners tackle lush single-track with hills, streams, and rocky sections; the course is marked with..

Redwood (Spring) Trail Run is held at the Chabot Space & Science Center in Oakland, California, featuring multiple distances from 5 miles up to 50K, plus a Half Marathon, Marathon, 30K, a 5K, and several youth events. The course winds through Redwood Regional Park, offering spectacular views along t..

The Western Pacific Marathon event, held at Quarry Lakes Regional Recreation Area in Fremont, California, offers runners a choice of half marathon, 10K, and 5K distances. The course is mostly flat, following the historic Western Pacific Trail, which was originally used in the 1800s to transport grav..

Bad Ass Backyard Ultra (B.A.B.U.) takes place at Dry Creek Parkway in Rio Linda, Sacramento, California. The event uses the traditional backyard ultra format: a 4.16-mile loop with a new loop starting each hour; anyone not in the start corral at the hour is eliminated, and the winner completes the m..

The Knickerbocker Canyon Trail Run takes place Saturday, March 28, 2026 at American River Overlook Park in Auburn, California. The event offers the following distances: 35K - 20.8 miles, 4,800 ft elevation gain Half Marathon - 13.3 miles, 3,000 ft elevation gain 10K - 6.1 miles, 1,150 ft elevation..

Set in the Marin Headlands, the Golden Gate Headlands Marathon, Half Marathon & 10K starts and finishes at the Historic Gunnery Range in Rodeo Valley, Mill Valley, California. The course traverses scenic single-track trails and fire roads, offering panoramic views of San Francisco Bay, the Golden Ga..

Diablo Trails Challenge is a trail-running event held at 1700 Castle Rock Road, Walnut Creek, CA, in support of Save Mount Diablo. The race offers multiple distances to suit all levels: 50K, half marathon, 10K, and 5K, plus a Remote Runner option. The course traverses Mount Diablo’s open-space trail..

American River Endurance Runs is a three-race ultra series from Folsom to Auburn, California, along the scenic American River Parkway. The flagship AR50 has become the second-largest 50-mile race in the United States, attracting veterans and newcomers, with companion 25- and 10-mile events finishing..

Taking place in Healdsburg, California, the TERREX Lake Sonoma weekend features three distances on April 11, 2026: the Lake Sonoma 50 Mile, the Lake Sonoma Marathon, and the Trail Sisters Half Marathon. The event blends competitive racing with a festival atmosphere, including an Elite division in th..

Romancing the Island Half Marathon & 10K takes place at Angel Island State Park, Belvedere Tiburon, California. The course is a hilly loop around the island: the half marathon runs the loop twice, the 10K once. Runners enjoy panoramic views of the Golden Gate Bridge, San Francisco, Alcatraz, the Eas..

Location: Calistoga, California, in Napa Valley. Distances: 50k, 35k, half marathon, and 10k. Atmosphere: a mountain-style trail ultra with a devoted community feel, starting and finishing on the Great Lawn at the Calistoga Fairgrounds.Course: four races depart the Fairgrounds, venturing into Robert..