When: Sat., Sept. 14 2013
All right, you gluttons for punishment, here's a gnarly one: the first-ever Big Sky Resort Ultramarathon, known as The Rut. There's a 50k and 12K course, each of which traverses the expansive beauty of Lone Peak. The 50K -- "not for the faint of heart" -- includes 8,200 feet of elevation gain, plus single-track through forest and jeep roads leading to the summit. Visit bigskyresort.com/events.