Cougar Mountain Trail Run Series

Bellevue, United States • 8 Aug 2026

Cougar Mountain Trail Run Series #4

The Cougar Mountain Trail Run Series #4 is scheduled for August 8, 2026, at King County's Cougar Mountain Regional Wildland Park in Newcastle, Washington. The event offers multiple race distances:

  • 5k
  • 14.5 miles
  • 26.2 miles

The park features rolling, runnable hills and a variety of trails ranging from narrow, technical single-track to wider, groomed routes. Course terrain passes through lush forest, fern-lined single-track, hills and marsh areas. The park is located about 15 minutes from Seattle and the registration and start area is at Sky Country Trailhead off 166th Way SE.

Online pre-registration is available through August 5, 2026, and event-day registration is offered. The series is organized by Seattle Running Club and Northwest Trail Runs and is the 21st annual series. Historically, the series has raised more than $250,000 for King County Parks and has contributed many hundreds of hours of trail work.

Aid stations are placed along each course at these mile markers:

  • 5k: 1.2 miles (no cut-off)
  • 14.5 miles: 3, 4.6, 7.1, 10.3 miles
  • 26.2 miles: 5.4, 6.9, 10.7, 14.2, 18.3, 24.8 miles

The race is part of the PNW Youth Trail Project series, where youth compete alongside other youth and adults and earn points in age and gender categories. Visit the organization's website for the most recent information.

Race information

26 mi
26.2-Mile
15 mi
14.5-Mile
5 km
Visit the organization's website for the most recent information.
Trail runs nearby

Experience the lush forests and rolling hills of Cougar Mountain Regional Wildland Park at this trail event near Seattle. Choose between 5k, 10.8 mile, and 19.5 mile distances on varied terrain ranging from technical to groomed trails.

Mud Mountain Trail Fest is a trail running event at Mud Mountain Dam in Enumclaw, Washington on July 11, 2026. It offers a 4 Miler and a 10K on forested trails described as moderately challenging.

Monthly trail races at Cougar Mountain offer a range of distances across a summer series and an October autumn event. The events raise funds for King County Parks and include USATF championship and youth races in August.

A 5K trail run and walk on Tiger Mountain with an out and back route over unpaved roads and a short cross country section. The event is clothing optional and is sponsored by Tiger Mountain Family Nudist Park.

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