Both the Half Marathon and the Marathon will use the Cenntenial Trail. There’s a short run (approximately 180 feet) from the start to the trail. Once on the trail you’ll turn right and head south towards the Snohomish Fitness Center at about 1.5 miles. You’ll turn around and then head north up to the second turnaround. From there you run back to the trail and to the finish line.
See what splits you need to run for hundreds of different marathons - adjusted for the specific terrain of each marathon, your goal time and pacing strategies.