The Grand Slam of Ultrarunning

Trail running continues to explode in popularity, and while shorter races will always be the most easily-accessible, participation in ultra trail races continues to soar. At the extreme end of the sport is the 100-mile distance. Despite the incredible difficulty, the idea of racing 100 miles on foot to truly test your mettle against the mountains and your fellow man captures the imagination of thousands of runners.

While there are plenty of 100-mile races to go around, a fabled few are so revered in the collective trail running consciousness that they've come to embody a bonafide bucket list. Unlike some road marathons that can accommodate thousands of participants, trail races have to cap the number of participants much much lower (sometimes below 100), meaning that to get into the most popular races, you must either qualify, enter a lottery, or both. 

One of the most venerated goals in ultrarunning is to complete the "Grand Slam" in one year. To count as a Grand Slam finisher, runners must "complete four of the oldest 100-mile trail runs in the US," according to Run100s.com. "The "Slam" consists of officially finishing three of these four: the Old Dominion 100 Mile Run, the Western States 100 Mile Endurance Run, the Vermont 100 Mile Endurance Run, the Leadville Trail 100 Mile Run, plus the Wasatch Front 100 Mile Endurance Run all in the same year," the writer continues.

In this guidebook, you'll find all five of these long-distance race routes outlined in detail, allowing you to start planning and dreaming of your own Grand Slam attempt!

Sources:
LeadvilleRaceSeries.com 
Run100s.com
Wikipedia.org
WSER.org