Cougar Mountain Trail Run Series (May)

Embark on an unforgettable trail running adventure at the Cougar Mountain Trail Run Series (May) on May 9, 2026, in scenic Bellevue, WA. This highly anticipated event, now in its 23rd year, invites runners to explore the lush, fern-lined single-track trails of Cougar Mountain Regional Wildland Park, a renowned training ground just 15 minutes from Seattle. Choose your challenge from two exhilarating distances: the 10.8-mile course with approximately 1900 feet of climb or the 5.1-mile option featuring around 550 feet of elevation gain. The courses offer a delightful mix of rolling hills, moderate climbs, and some steep but short inclines, winding through diverse terrain including marshes and wetland habitats, providing a true trail running paradise for all skill levels.

Runners can expect well-marked trails and a vibrant community atmosphere at the Sky Country Trailhead, where all races begin and end. Aid stations will be available along the route, with participants encouraged to bring their own refillable water containers to support sustainability. Beyond the personal challenge, this race is special for its significant contribution; a portion of every entry directly supports King County Parks, with the series having already raised over $265,000 and contributed hundreds of hours of trail work. Typical race day conditions in early May often bring pleasant highs around 65°F and lows around 47°F, with only a 10% chance of precipitation, creating ideal running weather.

Join the Seattle Running Club and Northwest Trail Runs for a rewarding experience that combines stunning natural beauty with a commitment to park conservation. Due to participant caps, early registration is recommended for this popular event, which concludes with post-race food and libations, including beer from Flying Lion Brewery.