Prepare for an epic challenge at the IMTUF100, a truly demanding 100-mile ultra-marathon set in the rugged Salmon River Mountains near McCall, Idaho, on September 19, 2026. Known as a "post-graduate level ultra," IMTUF is a qualifying race for both the Hardrock 100 and Western States 100, attracting seasoned ultrarunners seeking an authentic mountain adventure. The course is a loop that promises over 22,000 feet of ascent and descent, with some calling the footing "rough" and "downright brutal" at times. Expect a diverse and technical journey across eight high passes, featuring very steep climbs and descents, granite slabs, and even some boulder scrambling.

The breathtaking scenery is a constant companion, with pristine rivers, beautiful summits and ridges, and deep canyons showcasing the wild beauty of Idaho. Runners frequently encounter wildlife, including elk bugling during the peak rut, bears, wolves, lions, moose, and deer, adding to the remote feel of the race. Typical race day conditions in mid-September bring highs around 70°F and lows around 38°F, with a low 6% chance of precipitation, though runners should be prepared for potential temperature swings and "moon dust" on the trails in drier years. Starting and finishing at Jug Mountain Ranch, the race offers well-supported aid stations, though distances between them can be significant, especially at night. One unique aid station is even "goat-powered," with supplies packed in by goats.

IMTUF is celebrated for its commitment to the spirit of trail running, with race directors personally flagging the meticulously marked course. Finishers earn a classic belt buckle, a cotton hoody, homemade soup, and a craft beer six-pack, a testament to the grassroots passion behind this challenging event. Runners often describe the experience as mind-altering, fostering a profound sense of camaraderie. If you're seeking a genuinely tough, rewarding, and scenic 100-mile mountain race that will test your limits, IMTUF100 awaits.