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Ironstone 100K Course Guide

Ironstone 100K, billed as "A Savage Ultramarathon," is a point-to-point 63.4 miler from Canoe Creek State Park to Greenwood Furnace State Park, straight through the Ridge-and-Valley singletrack of Rothrock State Forest. There is no loop back to a familiar aid station and no drop bag waiting where you started. I will walk you through the course, the entry requirements you need to know about early, and a pacing and fueling plan built for the long unsupported stretch in the middle of the night.

⏵ At a glance

Ironstone 100K quick facts

Date
July 11-12, 2026
Location
Point-to-point, Canoe Creek State Park to Greenwood Furnace State Park, Rothrock State Forest, PA
Distance
100K (63.4 mi)
Elevation change
About 7,994 ft up and 8,169 ft down (organizer average across prior editions)
Cutoff
23-hour overall time limit
Entry
Qualifier required (a 50K finish within about 2.5 years) plus 8 mandatory volunteer hours to register, $149 entry, capped at 150 runners, first-come

These facts come from the official race site and the organizer's published course data. Aid station cutoff splits were not published in a form we could confirm, so check the current race-day details before you commit. Race logistics change year to year.

The course: point to point through Rothrock

Ironstone runs one direction only, from Canoe Creek State Park to Greenwood Furnace State Park, using the Standing Stone Trail, the Mid State Trail, and the Lower Trail through Rothrock State Forest. 63.4 miles, close to 8,000 feet of climbing and a similar amount of descending. There is no second lap to learn from. Whatever you meet on the trail, you meet once.

Broad Mountain: the climax of the course

The defining climb of Ironstone is Broad Mountain, taken via the Standing Stone Trail, roughly 1,400 feet up and 1,400 feet back down on rough, rocky footing typical of central Pennsylvania. This is the sharpest single test on the course, and it comes with everything else you have already run in your legs.

Get up and over Broad Mountain clean and you are through the hardest single obstacle of the day. Blow up on it and you are fighting the rest of the course on borrowed energy.

Indian Steps to Little Flat Tower: the unsupported stretch

Here is the part that actually decides most people's race: a five to six hour stretch from Indian Steps to Little Flat Tower with no aid station support, and for most runners this falls overnight. No crew, nobody handing you a cup, just you, your headlamp, and whatever you are carrying.

Plan this section like its own small race inside the race. Carry more food and fluid than the mileage alone would suggest, know exactly where you are on the map, and expect the hours to feel long. This is where "Savage" in the race name earns its place.

Rugged, remote, and rocky the whole way

Outside of the marquee climb and the overnight stretch, the rest of Ironstone is still rugged Ridge-and-Valley singletrack, remote and rocky, the kind of Pennsylvania trail that never quite lets you relax into a rhythm. There is no long flat stretch to bank easy miles on.

Respect the terrain from mile one. Pennsylvania ultras punish runners who treat rocky singletrack like a road race, and Ironstone is no exception.

Pacing strategy for a point-to-point, unsupported 100K

With nearly 8,000 feet of climbing, rocky singletrack throughout, and a long unsupported stretch that usually falls overnight, Ironstone punishes anyone pacing off a flat-ground number.

Pace Broad Mountain and the rocky miles by grade

Your flat-road pace tells you nothing about what a rocky 1,400-foot climb on the Standing Stone Trail is going to cost you, or what the technical descents will do to your legs afterward. Use a grade-adjusted pace to turn your real fitness into honest targets for Broad Mountain and for the rest of the rocky, undulating terrain, so you are not guessing at effort when it matters most.

Build a realistic finish window against the 23-hour cutoff

A 100K time from a runnable course will not translate directly to Ironstone. The climbing, the technical footing, and especially the unsupported Indian Steps to Little Flat Tower stretch all cost more time than raw distance suggests. A vert-aware finish prediction gives you a realistic window against the 23-hour limit, so you know roughly how much cushion you are working with heading into the overnight section instead of finding out the hard way.

⏵ Free tools to pace this course

Fueling strategy for the unsupported overnight stretch

Ironstone finishers are typically out somewhere between 15 and 23 hours, and the five to six hour gap from Indian Steps to Little Flat Tower has no aid at all. Your carrying capacity matters as much as your fitness.

Carbs: consistent, and enough to cover the gap

Aim for roughly 60 to 90 grams of carbohydrate per hour, pushed toward the higher end only if you have trained your gut for it on long runs. Because the overnight stretch offers no resupply, carry enough calories to cover that entire five to six hour window on top of your normal per-hour rate, not just enough to reach the next aid station like you would on a looped course.

Sodium and hydration: plan the unsupported miles like their own leg

Mid-July in central Pennsylvania can still run warm even overnight, so keep sodium in the 300 to 700-plus milligram per liter range depending on conditions and your own sweat rate. Treat the Indian Steps to Little Flat Tower stretch as a standalone hydration problem: figure out exactly how much fluid you need to carry to cross it safely, then add a margin, because there is no aid station to bail you out if you misjudge it.

⏵ Build your fueling plan

Get a carb, sodium, fluid, and caffeine plan per hour built for your weight, your goal time, and the unsupported overnight stretch with the free ultra fueling calculator. Browse the rest of the free running tools at the tools hub.

⏵ Train for it with Summit Line

Get a race-day plan built around YOUR fitness, this exact Ironstone course profile, and your projected splits. Summit Line reads your real training, builds a plan for the climbing and the unsupported miles, and rehearses your fueling so race day is something you execute, not guess at.

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Ironstone 100K FAQ

How hard is Ironstone 100K?

Ironstone 100K is a genuinely tough point-to-point ultra. You cover 63.4 miles and something like 8,000 feet of climbing and a similar amount of descending, on rugged Ridge-and-Valley singletrack through Rothrock State Forest, and you never loop back to a drop bag or a familiar aid station. The 23-hour cutoff is not generous once you account for the terrain, and a long unsupported overnight stretch in the middle makes this a race about self-sufficiency as much as fitness.

What is the hardest part of the Ironstone 100K course?

The climax of the course is Broad Mountain, climbed and descended via the Standing Stone Trail, roughly 1,400 feet up and 1,400 feet back down on rough footing. But the part that actually breaks people is the long overnight stretch from Indian Steps to Little Flat Tower, five to six hours with no support, deep into the night. Get through that section with your head straight and your legs under you, and the rest of the course is manageable.

Do I need to volunteer to run Ironstone 100K?

Yes, and this is worth knowing before you plan around this race. Registration requires a prior 50K finish within roughly the last 2.5 years and 8 mandatory volunteer hours, and you have to log those hours before you are allowed to register, not after. Budget for that ahead of time, ideally at Eastern States 100 or another ESTEA event, so you are not scrambling for volunteer slots the week entries open.

How should I fuel for Ironstone 100K?

Plan for a long day, likely somewhere in the 15 to 23 hour range depending on your finish, with a long unsupported stretch where nobody is handing you anything. Most runners do well on roughly 60 to 90 grams of carbohydrate per hour, and sodium in the 300 to 700-plus milligram per liter range depending on how hot mid-July central Pennsylvania is running. Because of the unsupported overnight section, carry more food and fluid than you think you need for that stretch specifically. Build your numbers with the free ultra fueling calculator before race day.

What are the cutoffs at Ironstone 100K?

The published overall limit is 23 hours. Individual aid station cutoff splits were not published in a way we could confirm for this guide, so do not assume even pacing gets you through, some sections (especially the unsupported overnight stretch) will eat more of your buffer than flat mileage math suggests. Confirm the current aid station schedule on the official site before race day.

Is Ironstone 100K a good first 100K?

Not really, and the entry requirements say as much: you need a 50K finish already on your resume just to register. Between the point-to-point format, the remote and rugged Rothrock terrain, the unsupported overnight stretch, and a finish rate that runs somewhere around 50 to 61 percent depending on the year, this is a race for someone who has already handled a tough ultra and wants a bigger, lonelier one.

This guide is independent and for planning only. The course details, dates, cutoffs, entry requirements, and aid stations come from public sources and can change year to year, so confirm the current specifics, including the volunteer-hour requirement, with the official race before you register or run. The fueling and pacing advice is general and not medical advice.