Why The Rocky Mountain Slam Is The Toughest Race Series In Ultrarunning

August 4, 2021

To complete the Rocky Mountain Slam, men and women have to finish four out of five annual races in the Rockies: the Bighorn 100 in Montana in June, the Hardrock 100 in Colorado in July, the Leadville Trail 100 in Colorado in August, the Wasatch Front 100 in Utah in early September and the Bear 100 in late September. Leadville and Wasatch are also part of the Grand Slam of Ultrarunning. Trail Runner