The 100 mile race climbs the Rim in four separate locations spending a lot of miles along the Rim, on top of the Rim and the challenging climbs up and down. Expect to climb a total of 22,000 feet along the way in the 100 mile race never below 5,000 feet and never above 8,000 feet in elevation. While other races are certainly at higher elevations, and/or with more climbing, they certainly do not contain as rugged a terrain that is found on this course. This is a VERY technical course in many areas, specifically the Highline Trail, Donahue and the soon to be revered, Myrtle Trail. Coupled with the mileage, the terrain, the moderate elevation, and the Arizona sun, this race will certainly take it's toll on each runner.