The Hardrock Hundred Mile Endurance Run is an annual ultramarathon held in the San Juan Mountains of Colorado. Covering a distance of 100.5 miles, the race features a challenging course with over 33,000 feet of elevation gain and loss. It typically takes place in July and attracts runners from around the world. Participants navigate rugged terrain, including rocky trails and high-altitude passes, with the highest point reaching 14,048 feet at Handies Peak. The event emphasizes self-sufficiency, requiring runners to carry essential gear and navigate using maps. The race is known for its tough conditions and stunning mountain scenery.