The Hardest Hike In America? We Backpack The Sierra High RouteChris Brinlee Jr7/16/15 2:20pm8335EditPromoteGo to permalink Stretching 200 miles through the Sierra Nevada, most of the High Route is off-trail, posing challenges both physical and mental as you attempt to navigate dangerous, unmarked terrain. It took us two solid weeks. Worth it? Well, at least the photos came out good.