Western Pacific Marathon

Fremont, United States • 28 Mar 2026

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 gravel for the Transcontinental Railroad construction. This scenic and accessible route provides an excellent opportunity for participants to achieve personal bests. The event supports the East Bay Regional Parks Campership Program and includes options for remote runners. It combines a rich historical backdrop with a well-organized race experience in a beautiful regional park setting. Visit the organization's website for the most recent information.

Race information

21 km
Half Marathon
10 km
10k
5 km
Visit the organization's website for the most recent information.
Trail runs nearby

Stevens Creek Striders Reservoir Run at Stevens Creek County Park in Cupertino, CA offers a Half Marathon (13.2 mi), an 11K (6.8 mi), and a 2.5‑mile Lollipop Loop along Stevens Creek and the reservoir. Runners navigate shaded Tony Look single-track and open Coyote Ridge vistas, with ascents on the h..

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..

South Hills Single Track Trail Run takes place at Calero County Park in San Jose, California. The event offers a full slate of distances: 1 mile kids run, 5K, 10K, 9 mile, half marathon, 16 mile, trail marathon, and 50K. The course blends single-track trails and dirt roads, showcasing oak trees, hil..

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..

The Mt. Umunhum Marathon, Race to the Top and Down, is a challenging trail running event held in Almaden Quicksilver County Park, San Jose, California. This marathon features a rugged course that begins at the Hacienda Entrance and ascends to the summit of Mt.Umunhum, one of the prominent peaks in t..