This 100K traverse through Pennsylvania’s Endless Mountains delivers 64 miles of technical single-track terrain that earned its reputation as one of the most challenging qualifiers for Western States 100. The course winds through Worlds End State Park and along sections of the legendary Loyalsock Trail, serving up 12,395 feet of climbing with a total elevation change of 24,790 feet across rocky hollows, creek crossings, and forested ridgelines.

The route showcases the rugged beauty of the region with multiple overlooks, cascading waterfalls, and dense forest canopy. Runners frequently spot bald eagles while traversing the rocky ledges above Loyalsock Creek. The technical terrain features roots, rocks, and steep climbs that demand respect and preparation.

Entry requires strict qualifying standards—participants must complete at least one 50K trail race within cutoff times in the two years prior to registration. Race directors review each application individually, as this is definitively not an entry-level event. Registration caps at 175 runners for the 100K distance.

The event also offers a 50K option covering 31.4 miles with 5,915 feet of climbing on the same challenging terrain. Both distances start and finish at Cliff Pavilion within the state park.

Twelve aid stations support runners throughout the course, with seven accessible to crews and three allowing pacer exchanges. Cutoff times are enforced strictly given the technical nature of the terrain.

As the anchor event of Pennsylvania’s Triple Crown series alongside Hyner 50K and Eastern States 100, Worlds End attracts serious trail runners seeking to test themselves against some of the most demanding terrain in the Mid-Atlantic.