The Skyrunner® World Series was launched in 2004 and has grown to represent one of the most extreme forms of running. The Series and the races within it are defined by altitude and technicality. 

The Merrell Skyrunner® World Series represents the highest level of skyrunning. Each race in the Merrell Skyrunner® World Series tests skill, endurance, and bravery. Courses are typically beetween 20 and 30km in distance with a cumulative elevation gain exceeding 2,000m. The courses combine runnable trail with highly technical terrain including sharp ridges, snowy climbs, and steep rocky descents. From the Andes to the Alps, the Skyrunner World Series selects only the best SkyRaces in stunning locations worldwide. This attracts the fastest and most fearless skyrunners, who strive to be crowned the best in the world.