Cougar Mountain 50K Course Guide

It packs about 7,200 feet of approximate climb into 31 miles of rolling forest singletrack, a substantial vert total for a course that never leaves a King County park just fifteen minutes from Seattle. The terrain itself is described by the organizers as rolling hills with a few moderate climbs and a few steep but short inclines, so the difficulty comes from repetition and cumulative elevation rather than any single defining feature.

The official course-maps page lists an approximate climb of 7,200 feet for the 50K, building steadily through the shorter distances in the same race family: 5.1 miles gains about 550 feet, 10.8 miles about 1,900 feet, 19.5 miles about 3,700 feet, and the 50K itself about 7,200 feet. That progression tells you the climbing accumulates fairly evenly across the distance rather than front- or back-loading.

Late October in the Seattle area typically means cool, damp conditions, so hydration for effort matters more than hydration for heat. Aim for roughly 50 to 75 grams of carbohydrate per hour and sodium in the 300 to 500 mg per liter range for typical fall Pacific Northwest temperatures. Aid stations are stocked with Skratch hydration products, and this is a cupless race, so bring a refillable container you can use at each stop. Build your numbers with the free ultra fueling calculator before race day.

The 50K and 19.5-mile distances both start at 8:00 AM, with a 7:00 AM early start option for runners who want extra time, and the course closes at 5:00 PM. That gives standard starters 9 hours and early starters 10 hours to finish the 50K. No intermediate aid-station cutoffs beyond the overall course closure are published, so pace with enough margin to comfortably beat that 5 PM close.

Cougar Mountain Regional Wildland Park is described by the organizers as a lush forest of fern-lined singletrack trails, with rolling hills over marshes and wetland habitats. Expect rolling terrain with a few moderate climbs and a handful of steep but short inclines rather than one long sustained ascent, on trails the Seattle Running Club uses as a regular training ground.

The generous 9-to-10-hour window and the well-marked, well-supported course, run by an established club with decades of experience on this exact terrain, make it a reasonable first 50K if you have some hill training under your belt. The roughly 7,200 feet of cumulative climbing is real for the distance, so build hill repeats and long runs with sustained vert into your training rather than assuming a Pacific Northwest forest course will be gentle just because it stays under 3,000 feet of elevation.