Worlds End 100k Ultramarathon

A 100k Western States Qualifier with epic views and remote singletrack through scenic Worlds End SP.

Trail Running Severe

100 km
3.4 km
3.4 km
1 day +
Low Point
257 m
High Point
624 m
Worlds End 100k Ultramarathon Map

The World's End 100k offers sweeping views, rocky singletrack, and quiet mountain streams on an epic tour of one of PA's most beautiful state parks. Large portions of this course, including the Loyalsock Trail, are open to hikers and trail runners throughout most of the year for those who may want to explore the area outside of race day. As a Western States Qualifier and one of the toughest, most scenic trail 100k's in the country, here's what you need to know if you want to register for this early-summer race.


The 63.8-mile loop is 95% singletrack or doubletrack, with only a few miles of road along the entire route. It boasts almost 12,400 feet of climbing, and as such, runners must qualify by completing any trail 50k race within the allotted cutoff in the prior two years. It's absolutely not a race for new to trail running, this is a graduation-level run. Runners who feel they have completed an adequately-challenging endeavor, say an FKT attempt or long run, are welcome to email the race director to request an exception from the rule. Timed races cannot qualify a runner to run Worlds End either.

Unique to this event, "Worlds End Ultramarathon requires eight (8) hours of volunteer service or a donation to our Pennsylvania Parks and Forest Foundation fund (PPFF)," the race site notes. The requirement must be fulfilled prior to race day, and there are no exceptions. "Our aim with our service hours is to bring our running community together and get people more involved with the trail racing scene but if doing trail maintenance or volunteering isn't in the cards, then we have another option for you," the site continues.

As of 2021, the male course record holder was Wesley Atkinson with a finish time in '19 of 10:50:38. Nicole Yokum is the latest women's record holder with a finish time of 13:23:05 in '21. Mid-pack finishers tend to complete the race between 17 or 18 hours though runners have a 19-hour cutoff, which happens to fall on midnight.

As with any reputable race, bandit runners are strictly prohibited, and runners who do not adequately display their bib numbers may be asked to stop and correct them. Headlights are also a mandatory requirement, and trekking poles, headphones, GPS devices, and similar are allowed if used safely and responsibly. The course also includes 12 well-staffed aid stations, though not all offer crew and drop bag access.

Worlds End Ultramarathon



High Exposure

3 out of 4

Some trail sections have exposed ledges or steep ascents/descents where falling could cause serious injury.


3 out of 4

Little chance of being seen or helped in case of an accident.

Best time to visit

March, April, May, June, July, August, September, October, November

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