Race Overview The NUTT Endurance Challenge 50k is a 31 mile multi-loop trail ultramarathon on mostly single-track/double-track at the amazing Western Slopes of Massanutten Mountain, maintained by the Shenandoah Valley Bicycle Coalition. You will complete five 10k figure-eight loops. There is an aid station every 5k, where you can also pass by your drop bags for self-support.  The […]