Grand Ridge 5M, Half-Marathon, Marathon and 50K Trail Run

November 14, 2015 in Issaquah, Washington


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Online pre-registration closes 11/12 at 11:59pm.


Join us for a trail run at Grand Ridge Regional Park, just across I-90 from Tiger Mountain. A great trail system awaits.



The course starts and finishes at Grand Ridge Trailhead, just off of I-90 Exit 20 (see directions tab) in Washington. It begins with a wide double track until you head north into the hills on the recently built singletrack trails. These are some of the nicest trails we have encountered in the Northwest.


We offer 5 Mile, Half-Marathon (13.1 Mile), Marathon (26.2 Mile) and 50K trail run options. The aid stations are fully stocked with water, Nuun, Clif product, PBJ sandwiches, fruit, cookies, crackers and pretzels. As always, at the finish there will be a full variety of post race foods awaiting you.



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5 Mile - $30

Half Marathon - $41

Marathon - $48

50K - $53


* Add $5 after 10/31 11:59pm, add $10 day-of if event has not sold out.



The race will be held at Grand Ridge trailhead, Exit 20 off of I-90 in Issaquah, Washington. The address is 27000 SE 79th St, Issaquah, WA 98027. If you are coming from I-90 Eastbound, take Exit 20 High Point way and take a right. If you are coming from I-90 Westbound take a left.  Parking is along the road from the start location outward, and since there will be many runners, please make sure to arrive early so you have plenty of time to walk to race start. We encourage you to consider carpooling too. 


Start times:  50K and Marathon: 7.45 am (no early starts)

Half-marathon: 9.00 am, 5 mile: 9.20 am

Pre-run briefing 15 minutes before each start

Day of run registration and check in: 6.45 am-start

Course closure: 4.30 pm

Course Map

Trail Running at Grand Ridge Park in Issaquah Washington5 Mile (1 orange loop)

Click on image to enlarge.


The 5 Mile Loop is essentially one large lollipop loop that follows singletrack trails up to the Issaquah Highlands ballfields and back down. The singletrack trails are fairly wide and passing runners should not be an issue. The courses will be well marked with streamers, turn flags, and direction signs at intersections. Elevation gain is 750 feet.


Half-marathon (1 purple loop)

The Half-marathon is a lollipop loop with an extension that traverses Grand Ridge and back. Elevation gain is approximately 2000 feet.


Marathon (2 purple loops)

The Marathon course is two loops of the Half Marathon Course. See here for Kevin Yetman's GPS profile.


50k (2 purple loops + 1 orange loop)

On the 50K course you will do two half-marathon loops, then a 5 mile loop for a total of 31.2 Miles (50k).


The course will be very well marked and intersections labeled with arrows to ensure runners do not get lost. Elevation gain is about 5050 feet for the 50K.


Read about how we keep the races green here.


We are dedicated to the responsible enjoyment and active stewardship of the outdoors, and we encourage you to "leave no trace behind" by taking all trash with you. The park rangers always appreciate it when racers follow the marked course and keep the trails clean, and they are much more likely to grant permission for us to put on races at the same location if the trails are kept in good condition.


The trails will be open to other users during the event, hikers and cyclists. Please be courteous, you will unlikely encounter more than a few. Where the trails are narrow, please let other participants pass you if they want to get by. It is a passing runner's job to tell the person in front that they wish to pass.


For refunds/cancellations please see our policy.


Photos and results from trail runs previously held can be found on the photos page and results page respectively.


Produced by 4th Dimension Racing