Hosted by Seattle Running Club and Northwest Trail Runs, the Cougar Mountain Trail Run supports King County Parks. The Cougar Mountain courses gradually get longer throughout the series. Run through a lush forest of fern-lined single-track trails.

Join Northwest Trail Runs for a fun 5k or 10k with a cause at Run with the Kokanee on a flat and fast course at Lake Sammamish State Park and East Lake Sammamish Trail.

Join the Greater Bellingham Running Club for a Monday “all paces” trail run at varying locations around the greater Bellingham area.

Produced by Go Beyond Racing, the Portland Trail Series is a super-cool, low-key series of trail running races held in Forest Park in Portland. Three five-race Series (Spring, Summer and Fall) are held Wednesday evenings from May-October, and each race covers a different, challenging course, ranging from 4-7 miles.

Produced by Run Wild Adventures, run a very scenic 5k trail run that starts and finishes at Silver Falls' south falls day use area.

Produced by Run Wild Adventures, run a scenic 7 mile, Marathon, or 50K in Silver Falls State Park. These courses are challenging, but quite possibly the most amazing and beautiful on the west coast!

Mud & Chocolate Fall Weekend | 4.5 Mile Run

Join Northwest Trail Runs for a 5k or 10k trail run at lush and green Carkeek Park. Carkeek is home to six miles of fun, roller-coaster trails that traverse the forest!