Grand Ridge Marathon, Half Marathon, 5-Miler & 50K

Saturday, November 9, 2024 • Issaquah, WA • Course Map

Nestled among the pristine forests and wilderness that lie just a short drive east from the urban streets and skyscrapers of nearby Seattle, Washington’s Grand Ridge Regional Park offers 1,200 acres of pristine woodlands filled with moss-covered boulders, sword ferns and western red cedar trees, some of which have trunks that reach up to five feet in width.

This natural setting that serves as a transition of sorts between the urban and rural environments forms the backdrop for the late summer running of the Grand Ridge Marathon, Half Marathon, 5-Miler and 50K, a series of trail races that take runners on a challenging, out-and-back route into the park and back out again.

Organized by 4th Dimension Racing, a locally based running and race management company that features the Grand Ridge Half as part of its Evergreen Trail Runs series — which also includes half marathon races in Lake Sammamish and Taylor Mountain nearby — the Grand Ridge races are the fall counterpart to the spring race.

Runners in the half marathon, like those in the 5-Mile and 50K runs, follow an out-and-back route that starts and finishes just off Exit 20 from Interstate 90, roughly 20 minutes east of downtown Seattle, and just east of the Issaquah Highlands residential development.

Entrants are asked to park along the road just off the exit (organizers say there should be plenty of parking available for all runners), where the starting line lies just a short walk from the parking lot.

From the starting area, runners next head into Grand Ridge, following the winding trails as they zig-zag along uneven, up-and-down terrain. Runners in the half marathon can expect an overall elevation gain of about 2,000 feet over the course of the race, which takes runners first westward and then northward along the park’s mostly single-track trails, which are home to cougars, owls, bears and other wildlife.

Once runners reach the turnaround point at the northernmost aid station, they then head back along much of the route they’ve just run, with the exception of a brief loop in the early part of the course. The finish line lies back at the starting area, where a variety of post-race food awaits.

Race Weather & Climate

Located in northwestern Washington state, just over 17 miles east of Seattle, Issaquah typically sees some of its wettest weather of the year in November, a month that has brought record temperatures here as low as 4°F (in 1955) and as high as 76°F (in 1949).

On race day (Nov. 9), the average low is 35ºF and the average high is 47ºF.

Course Map

See the race route map for the Grand Ridge Trail Half Marathon here.

Starting Time

  • 7:30 AM – 50K, full marathon
  • 8:15 AM – half marathon
  • 9:30 AM – 5-mile


  • $60 – $75 for the half marathon
  • $70 – $85 for the full marathon
  • $80 – $95 for the 50K
  • $30 – $45 for the 5-mile


To reserve your spot in the November 2024 running of Issaquah’s Grand Ridge Marathon, Half Marathon, 50K or 5-mile race, register online at here.

Official Race Website


Ever run in the Grand Ridge Half Marathon? Share your impressions here, or post your review in the Comments below.

See more races in: November, Washington