Grand Slam of Ultrarunning Series 2026

The Grand Slam of Ultrarunning requires participants to complete four 100-mile races within a single summer, culminating with the Wasatch Front 100 as the mandatory final event. Prior to Wasatch, runners must have officially finished three of these four races: Old Dominion, Western States, Vermont, and Leadville. All participants must also register for their intended races during each event's standard registration period, including the Wasatch race. The concept originated with Fred Pilon of Ultrarunning Magazine, who sought to connect the nation's oldest 100-mile trail races into a unified challenge. Wasatch was chosen to host the series finale as it occurs last on the summer schedule, and its race committee continues to oversee the challenge. Awards are presented at Wasatch, in addition to the race's traditional finisher plaques and belt buckles; the Grand Slam award itself is a sculpted eagle bearing the runner's name and achievement. Tom Green was the inaugural recipient, and Stan Jensen's enduring Grand Slam website continues to feature trivia, narratives, images, and series statistics.