One of the East Coast's toughest 100Ks — a Western States qualifier through Pennsylvania's relentless Loyalsock wilderness
Other trail races within 189 miles
The Worlds End 100K is one of the East Coast's most demanding and coveted ultramarathons, looping through the Loyalsock State Forest and Worlds End State Park on predominantly technical singletrack. Following the famed Loyalsock Trail and connecting side trails, the course delivers 12,400 feet of gain across rocky hollows, narrow hemlock corridors, swamp-like plateaus, and cascade-filled gorges. Highlights include Canyon Vista, the Ketchum Run Gorge, High Knob's panoramic overlook, and Angel Falls — the tallest waterfall on course. A Western States 100 qualifier and the centerpiece of the Pennsylvania Triple Crown of Mountain Running, this race has sold out in under 6 minutes for over a decade. Requires a prior 50K finish to enter.
Experienced ultrarunners
Forksville, PA, United StatesMay 30, 2026

Must complete an approved qualifier event within the qualification window
Find a qualifying raceMust have completed at least one 50K trail race within the advertised cutoff time, within 3 years of the registration date. Race results must be publicly available online (no timed events). Submit race name and direct results link during registration. Committee reviews each application.

| Location | Mile | Elevation |
|---|---|---|
Start Start | 0.0 | 1,112 ft |
High Rock Aid Station | 3.8 | 1,864 ft |
Iron Bridge Aid Station | 11.1 | 1,355 ft |
Devil's Garden Aid Station | 14.5 | 1,788 ft |
Worlds End Aid Station | 18.4 | 1,158 ft |
Canyon Vista Aid Station | 21.2 | 1,755 ft |
Coal Mine Aid Station | 24.8 | 1,768 ft |
Alpine Vista Aid Station | 27.5 | 1,749 ft |
High Knob Aid Station | 34.3 | 1,985 ft |
Jackson Flats Aid Station | 37.4 | 1,158 ft |
McCarty Aid Station | 42.8 | 1,657 ft |
The Gate Landmark | 44.0 | 1,759 ft |
Brunnerdale Aid Station | 48.7 | 1,276 ft |
The Gate Aid Station | 53.0 | 1,759 ft |
Fern Rock Aid Station | 57.9 | 1,841 ft |
Worlds End Finish | 63.9 | 1,138 ft |
Sign in to see cutoffs, crew access, drop bags, and services for every aid station.
No pets allowed on the course. Pets are welcome at the start/finish area and with crews at aid stations but must be leashed within the state park.
Camping available at Worlds End State Park (same park as start/finish line) — cabins and campsites bookable via ReserveAmerica. Loyalsock State Forest also offers roadside, rustic, and primitive backpacking campsites (permit required via DCNR). Pioneer Campground and several B&Bs and motels available within a few miles in Forksville/Dushore.
Race day falls on Memorial Day weekend in late May when Pennsylvania's Endless Mountains transition from spring to summer. The 5AM start means 100K runners face cool pre-dawn temperatures in the 45–55°F range before the day warms to highs of 65–85°F (18–29°C). Late finishers return to cool-to-cold conditions near or after midnight. Historical data shows mostly dry conditions, but afternoon thunderstorms are possible and spring weather shifts quickly. Wet rocks on the technical singletrack significantly increase difficulty.
Daytime highs can exceed 85°F in late May; midday sections on exposed ridges amplify heat stress during the middle third of the race
5AM start and potential midnight finish bracket the race with cold conditions; mid-40s°F possible at both ends for slower runners
Spring thunderstorms possible; wet rocks on technical singletrack dramatically increase difficulty, especially on technical descents


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