The course consists of a 5.2 mile loop, all on single-track trails. The course is entirely flat, on trails adjacent to the Willamette River. Most sections of the course are wooded,muddy and wet. The 50K will cover the loop 6 times, the 25K will cover the loop 3 times, the 10M will cover the loop twice (yes, that makes the distance 10.4 miles), and the 5M will cover the loop once (actually 5.2 miles)