Prepare to challenge yourself amidst the stunning Pacific Northwest landscape at the Cougar Mountain Trail Run Series on August 8, 2026, in Bellevue, WA. This well-established event, known for its vibrant local running community and dedication to King County Parks, offers distances for every trail enthusiast: a demanding 26.2M marathon, a challenging 14.5M, and a swift 5K. Typical race day conditions in early August are pleasant, with highs around 78°F and lows around 58°F, and only a 3% chance of precipitation.

The courses wind through King County's Cougar Mountain Regional Wildland Park, immersing runners in a lush forest of fern-lined single-track trails, wide groomed paths, and marshland habitats. Expect a dynamic experience with rolling hills, moderate climbs, and some steep, short inclines that contribute to significant elevation gain, earning the course a reputation for being hilly, yet runnable. While sweeping vistas are not the primary feature, the serene beauty of the forest itself provides a captivating backdrop for your run. Aid stations are strategically placed along the longer routes, typically offering water, electrolyte drinks, and various snacks, but remember this is a cup-free event, so bring your own refillable hydration system.

Beyond the race itself, the Cougar Mountain Trail Run Series stands out for its profound community spirit and commitment to conservation, having raised over $265,000 for King County Parks and contributing hundreds of hours in trail work. Runners frequently praise the well-marked trails and the supportive atmosphere, often noting it as an ideal race for those training for fall marathons or ultras. Finish your race at the Sky Country Trailhead with a sense of accomplishment and enjoy the post-race festivities, including food and refreshing beverages.