Turquoise lakes, kaleidoscopic wildflowers, bursting waterfalls, plush singletrack trails and endless alpine vistas. If these are qualities you seek in a mountain run, then Colorado’s Four Pass Loop (4PL), a classic adventure running linkup through the jagged Elk Mountains just south of Aspen, is one for your bucket list.
The route entails 27 miles of singletrack trails and 8,000 feet of elevation gain as it circles some of the most photographed peaks in North America. For trail runners who wish to tackle it in a day, it’s a robust but enjoyable high-altitude endurance test piece.
I first ran it solo two summers ago, and it’s so special that I had to go back again, this time joined by friend and frequent adventure partner Brian Metzler, Competitor’s editor in chief. Click through the photos below to see how our amazing day went down and check out this map of the route.