Are dogs allowed on the course?

No, dogs are not permitted on the course due to USATF sanctioning and insurance requirements.

Is the event cup-free?

Yes, the series is cup-free to reduce waste, so runners must bring their own refillable water containers for use at aid stations.

What happens if I cannot register online before the deadline?

Day-of registration is available at the event starting at 7:00 AM if you miss the online registration window.

Are there refunds if I cannot attend?

No, there are no refunds provided for the race series.

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Cougar Mountain Trail Run Series (October)

Saturday, October 31, 2026Bellevue, WA5K – 50K

The Cougar Mountain Trail Run Series offers a diverse range of distances set within the lush, fern-lined forests of King County's premier trail running destination. Located just 15 minutes from Seattle, the course features a mix of rolling hills, moderate climbs, and short, steep inclines that challenge runners of all experience levels. Participants can choose between the Short and Long series, with distances building throughout the summer months to help prepare for fall marathons and ultras. The series is deeply rooted in community, supporting King County Parks through donations and volunteer trail work. Beyond the trails, the event fosters a festive atmosphere with post-race refreshments, including local beer, and special themed challenges like the October costume contest. Whether you are chasing a USATF championship title or simply enjoying the scenic single-track, this 21st annual series provides a quintessential Pacific Northwest trail experience.