100k Overview - Worlds End Ultramarathon

worlds end 100k

run like there's no tomorrow

worlds end 100k

The course is predominantly rugged single-track that winds it’s way through the Endless Mountains in the Loyalsock State Forest and Worlds End State Park. Your effort will reward you with beautiful overlooks such as High Rock Vista, Canyon Vista, Upper and Lower Alpine View, Kettle Creek Vista, and High Knob Overlook – along with spectacular cascades and falls like Double Run, Dry Run Falls, Rode Falls and Lee’s Falls in the Ketchum Run Gorge, just to name a few. You’ll pass many interesting rock formations like Split Rock, take in the tranquility of Sones Pond and climb a wooden ladder along side Rode Falls. You may even see a bald eagle soar beside you as you traverse the rocky ledge of trail that overhangs the Loyalsock Creek.

This course can be described as “hilly” or “rolling” with it’s steepest sustained climb only being about 1,000 rocky feet. The deceptive part is that there is a never ending supply of shorter climbs that the trail throws at you to give an unexpected overall elevation gain of about 12,400 feet. Combine this with the often rock strewn, technical trail along with the number of times you’ll stop to take in the scenery, and you’ll quickly realize this isn’t a course you’ll try to set any personal records on.

The race was designed around the famed Loyalsock Trail but to complete the loop back to Worlds End State Park, you’ll spend plenty of time exploring side trails of equal beauty. The course runs deep in the Pennsylvania hills with rocky hollows, diverse forests, narrow gorges, and endless views – enough eye candy to keep you busy for your entire run. But don’t linger too long at any one place, you only have 19 hours to complete this race.

PA Triple Crown of Mountain Running

This brutal season long race series requires participants to complete the Hyner Challenge 50k, Worlds End 100k, and Eastern States 100, all within the same calander year.

2026 Western States 100 Qualifier

We are excited to announce that the Worlds End 100k continues to be a Western States 100 Mile Endurance Run Qualifier. One of only a handful of 100k qualifiers on the east coast.

Qualification Standards

The difficulty of the terrain means this is NOT an entry-level race. Each potential participant will be reviewed by the race directors after we receive the completed registration. At a minimum, all participants must have completed at least one 50k trail race within the advertised cut-off time before signing up. This must be within 3 years of the registration date.

If you have a race that is not a 50k but has a high degree of difficulty, it may be an exception to the above standard – just email us to find out if the race may qualify you. Be sure that your race is an official race with results published on a publicly available website. Timed races can not be used as a qualifying race. You must have completed a qualifying race before registering.

Qualification Standards

The difficulty of the terrain means this is NOT an entry-level race. Each potential participant will be reviewed by the race directors after we receive the completed registration. At a minimum, all participants must have completed at least one 50k or longer trail race within the advertised cut-off time before signing up. This must be within 3 years of the registration date.

If you have a race that is not at least a 50k but has a high degree of difficulty, it may be an exception to the above standard – just email us to find out if the race may qualify you. Be sure that your race is an official race with results published on a publicly available website. Timed races can not be used as a qualifying race. You must have completed a qualifying race before registering.

Registration

Registration Date: December 5, 2026
Registration Opens: 6:00PM
Platform: Runsignup
Registration Closes: May 28, 2027

Registration for the 2027 Worlds End Ultramarathon opens December 5, 2026 at 6:00PM using RUNSIGNUP as our preferred registration platform. The price will to be $210 + registration fees. We have a 200 person capacity limit and the race registration is first come, first served. There is a qualifying standard for the 100k race that must be met prior to signing up (see above).

Historically, the demand for this race has been extremely high for over 11 years – which means we sell out between 3 and 6 minutes every year. If you do not have a Runsignup account, take a moment prior to registration opening and set up an account. This will ensure you have the best chance of getting into the event. During registration, you will need to provide the name of your qualifying race and a link to the results where we can verify your name and time. Do not put in a general website link but the specific link to the results where we can search for your name. You may also use a link to your Ultrasignup account to verify your race results.

The wait list opens immediately after the race fills to capacity. While the wait list can be as long as the number of participants in the event, we tend to work our way through a large majority of the names on the list as we draw closer to the event. Don’t be afraid to put your name on the wait list and train like you’re going to race on race day.

*Note: Qualifying criteria are in place for event safety, manageability, and so that all participants are set up to have a positive race experience. Those not meeting the requirements will not be allowed entry into the race.*

Event Information

Event Date: June 5, 2027
Start Time: 5:00AM
Cutoff Time: 12 Midnight (19 hours)
Start & Finish Location: Cliff Pavilion at Worlds End State Park in Forskville, PA

The 2027 Worlds End 100k will be held on June 5, 2027, starting and finishing at Worlds End State Park. Parking for the event is located one mile from the park at the Sullivan County Fairgrounds. A shuttle service between the fairgrounds and the park will be provided throughout the day for both runners and crews alike.

Use the buttons below to find out more information:

Event information last updated: 3 June 2026

Refund Policy & Wait List

We believe trail running should be for everyone, no matter your financial background. Our goal is to make sure runners feel supported and empowered to take on this adventure without worrying about breaking the bank. With that spirit in mind, we offer the following refund options:

We will offer a 100% refund minus processing fees until December 31, no questions asked.
To keep things fair while still being able to support the volunteers, logistics, and community efforts that bring this race to life, after the initial full refund window we will refund 50% of your entry fee minus any processing fees until April 2.
Between April 3 and May 21, we will refund 25% of your entry fee minus any processing fees.
No refunds after May 21.

Please note that registrations can’t be transferred or deferred between race distances, to another runner, or to a future race. If you need to request a refund, just log in to your registration profile and submit your request there. We put a lot into making this event happen out in the PA Endless Mountains, so please consider these details carefully before registering.

As a Trail Sisters Approved race, we will continue to offer a pregnancy & postpartum refund as we have in the past. Whether planned or unplanned, expected or unexpected, start or end of a pregnancy, healing and recovery time are required for a women’s overall health. Please contact us for a refund option if you’re past the full refund date.

When the event reaches it’s capacity, you’ll have the option to joining the wait list. When a spot opens, Runsignup will automatically email an invitation to the next person in line, based on when they joined the list. If you receive an invite to join the event, you’ll have 48 hours to accept or decline it – after that, the offer expires and moves on to the next runner on the wait list.

relentless and brutally epic

Our Story

Iron Forged Runners is a grassroots organization based in Pennsylvania, committed to fostering a passion for trail running. Our mission is to inspire runners by offering races that challenge their limits, encouraging personal growth and resilience through demanding and rewarding events. Additionally, we aim to raise awareness of the beauty and accessibility of Pennsylvania’s State Parks and Forests, encouraging more people to explore and appreciate these outdoor treasures.

Worlds End Ultramarathon + Black Forest Ultra 100k + Pennsylvania Triple Crown of Mountain Running + The Black List