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⏵ Course guide · Colorado ultra

Indian Creek Fifties Course Guide

The Indian Creek Fifties is the oldest race in the Human Potential Running Series, a Front Range fall classic on seldom-used montane singletrack out of Indian Creek Campground near Sedalia, Colorado. It is not one big mountain. It is a steady drumbeat of rolling climbs at altitude that adds up fast, with a couple of hot, exposed stretches that catch people out. I will walk you through the course first, then give you a pacing and fueling plan that fits the vert and the thin air. There are free calculators along the way to dial in your own numbers.

⏵ At a glance

Indian Creek Fifties quick facts

Date
Saturday, October 17, 2026 (typically mid-to-late October)
Location
Indian Creek Campground, CO Hwy 67, Rampart Range, Pike National Forest, Sedalia, CO
Distances
50 mile · 55K · 15 mile · 5 mile
Elevation gain
55K: about 7,000 ft · 15 mile: about 2,673 ft · 50 mile: roughly double the 55K (confirm with the race)
Altitude
Roughly 5,800 to 8,100 ft, averaging around 7,000 ft
Start
50 mile and 55K at 6:00 AM MDT · 15 mile and 5 mile at 8:00 AM MDT
Cutoff
14-hour limit for the 50 mile and 55K (8:00 PM finish), with intermittent aid-station cutoffs
Qualifier
Has carried a UTMB Index listing in past years; not a Western States qualifier (under 100K)

These facts come from the Human Potential Running Series race page, UltraRunning, RunSignup, and firsthand race reports. The 50 mile total vert and the exact intermittent cutoffs shift a little year to year, so confirm the current date, cutoffs, and aid stations in the race-day details before you commit. Race logistics change.

The course: where Indian Creek is won and lost

Everything starts and finishes at Indian Creek Campground on CO Highway 67, and the route threads seldom-used Front Range singletrack through the Rampart Range and Pike National Forest. You climb from lower montane grasses and red rocks up into lodgepole pine and aspen, roughly 5,800 to 8,100 feet, with the 50 mile running a similar big loop twice. The 55K and 15 mile take shorter cuts of the same trail system. Aid sits at the 9.9, 15.2, 20.75, 24.1, 33.9, 39.1, 45.25, and 50.82 mile points on the 50 mile, with the Indian Creek stops (15.2 and 33.9) doubling as crew and drop-bag access.

The altitude is the hidden climb

There is no single monster ascent here, and that fools people. What gets you is the elevation. The whole course lives up around 7,000 feet, topping out near 8,100, so even the flat and runnable sections cost you more air than they would back home. If you live near sea level, plan for the thin stuff to slow your climbing and spike your heart rate, and respect that early when everything still feels easy.

The climbing comes as a steady drumbeat of rolling montane grades on dry, dusty singletrack, not one big mountain you tick off and forget. It adds up fast: roughly 7,000 feet over the 55K, and close to double that on the 50 mile two-loop. Hike the steeper pitches with purpose, keep your effort even, and let the altitude set your ceiling instead of fighting it.

The exposed gap: hottest, driest, hardest

The piece that wrecks days is the long, open stretch out on the far side of the course, the kind of dry, exposed grassy and scrub-oak terrain where there is no shade and the sun just sits on you. Firsthand reports from the 50 mile single out the run between the far aid stations as the spot where the heat and the lack of water turn a good day sideways. People get water-obsessed out there for a reason.

This is where you cannot count on the aid spacing to save you. Leave the crew and drop-bag stops topped off on fluid and sodium, and carry enough to cross the gap with margin, not just barely. October can start in the 30s and still bake by midday on those open miles, so dress for cold at 6:00 AM but plan your hydration for real heat.

The descents and the second loop

What goes up on this trail system comes back down, and the descents are runnable if you saved something for them. Rolling montane singletrack with rocky, sometimes technical patches means quick feet matter as much as fitness, especially late when your legs are cooked and you stop picking up your feet. Trash your quads early and the back half turns into a careful, slow shuffle.

On the 50 mile, the second loop is the whole race. Plenty of runners say the back half is actually the better trail, but you only get to enjoy it if you paced the first loop with discipline and kept eating. Get to the start of loop two with legs and a working stomach and you can finish strong through the fall color. Arrive there already cooked and the altitude makes the climb out a long afternoon.

Pacing strategy for a high-altitude, vert-heavy ultra

With roughly 7,000 feet of rolling climb in the 55K (and close to double on the 50 mile), all of it above 5,800 feet, Indian Creek is about managing effort, not hitting a pace chart. Run by feel and let the altitude cap your output, not your ego.

Pace the climbs by grade, not by the watch

Your flat-ground pace is meaningless on these rolling montane grades at altitude. What matters is grade-adjusted effort: hold a steady output you can actually sustain uphill, and hike the steep pitches without feeling guilty about it. The classic blowup here is running the early rollers too hard because the thin air has not bitten yet, then falling apart on the far loop. Use a grade-adjusted pace to turn your real fitness into honest climbing and descending targets so you do not torch the first half.

Build a vert-aware, altitude-honest finish window

Do not guess your Indian Creek finish off a road 50 mile time, and do not even trust a sea-level trail time. The thousands of feet of climbing, the technical footing, the heat on the open miles, and the altitude all add real minutes. A vert-aware finish prediction gives you a realistic window, then you can work back into the intermittent cutoffs so you know exactly how much buffer you have at each far aid station instead of finding out the hard way.

⏵ Free tools to pace this course

  • Grade-adjusted pace calculator to turn your flat fitness into honest targets for the rolling climbs and the descents.
  • Race-time calculator for a vert-aware finish prediction on this course’s climbing, so you can plan against the 14-hour limit and the intermittent cutoffs.
  • Race-equivalent calculator to turn a recent race result into an Indian Creek goal you can actually hold at altitude.

Fueling strategy for altitude, heat, and the long gaps

The 55K runs for most people in the eight to ten hour range, and the 50 mile is a long day right up to the 14-hour wall. Add altitude that kills your appetite and exposed miles between aid, and carbohydrate, sodium, and fluid matter as much as fitness.

Carbs: steady, trained, and easy to swallow

For a long day like this, aim for around 60 to 90 grams of carbohydrate per hour, and only push the higher end if your gut is genuinely trained for it. Altitude blunts your appetite and slows digestion, so steady, easy-to-swallow calories beat big late doses you will not want to choke down on the climbs. Practice your exact race-day carb rate on long runs at effort so 80-plus grams an hour feels normal, not like an experiment you are running on race morning.

Sodium and fluid: carry across the gaps

Lean toward the high end on sodium, often around 500 to 700 milligrams per liter of fluid, and more if you sweat heavy or salty, because that midday sun on the open sections pulls it out of you. Just as important, the Indian Creek crew and drop-bag stops sit far apart with exposed trail between them, so leave them topped off and carry enough fluid to cross with margin instead of rationing to empty. Weigh yourself before and after a long run to find your real sweat rate, then build the plan around your own number.

⏵ Build your fueling plan

Get a carb, sodium, fluid, and caffeine plan per hour built for your weight, your goal time, and the Indian Creek altitude and heat 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 Indian Creek course profile, and your projected splits. Summit Line reads your real training, builds a plan for the rolling vert and the altitude, and rehearses your fueling so race day is something you execute, not guess at.

Start free →Explore the demo

Indian Creek Fifties FAQ

How hard is the Indian Creek Fifties?

It is a legitimately hard Front Range ultra, and the altitude is what makes it harder than the raw numbers suggest. The whole course sits up around 5,800 to 8,100 feet, so even the runnable parts cost you more than they would at sea level. The 55K stacks roughly 7,000 feet of climbing into about 34 miles, and the 50 mile runs a similar profile twice. Add long, exposed, sun-baked stretches between a couple of the aid stations and you have a day that rewards patience, climbing legs, and a fueling plan you actually rehearsed.

How much climbing is in the Indian Creek Fifties?

The 55K has somewhere around 7,000 feet of total elevation gain over roughly 34 miles, which is a lot of vert for the distance. The 50 mile is built as essentially two big loops, so figure on close to double that, give or take, and confirm the current number with the race because the exact figure shifts a little year to year. The 15 mile carries about 2,673 feet of gain. None of it is one giant mountain climb. It is a steady drumbeat of rolling montane singletrack that adds up fast.

What are the cutoff times for the Indian Creek Fifties?

The 50 mile and 55K both run on a generous 14-hour limit, with everyone needing to be in by 8:00 PM after the 6:00 AM start. There are intermittent cutoffs at points along the course too, so you cannot bank all your buffer for the end, especially out at the far aid stations. The 15 mile and 5 mile start at 8:00 AM and have plenty of time. Always confirm the exact intermediate cutoffs in the current race-day details before you toe the line.

How should I fuel and hydrate for the Indian Creek Fifties?

Treat it as a long day at altitude with some genuinely exposed, hot miles between aid. Most runners do well on roughly 60 to 90 grams of carbohydrate per hour, leaning to the higher end only if your gut is trained for it. Altitude tends to blunt your appetite, so keep intake steady and easy to swallow rather than gambling on big late doses. Two of the aid stations (Indian Creek, at the crew and drop-bag stops) sit far apart with sun-baked trail in between, so carry enough fluid and sodium to cross those gaps instead of rationing to the next one.

What is the terrain and weather like at Indian Creek?

The course is seldom-used Front Range singletrack through montane forest, climbing from lower montane grasses and red rocks up into lodgepole pine and aspen, with big views and peak fall color in October. Footing is mostly dry, dusty trail with some rocky, technical sections, not smooth buffed path. October weather is classic Colorado high country: it can start in the 30s Fahrenheit and warm fast, and a warm, sunny day on the exposed sections can feel a lot hotter than the air temperature. Plan for cold at the 6:00 AM start and real heat by midday.

Is the Indian Creek Fifties a good first ultra?

The 55K can be a strong goal race for a prepared first-timer, and the 14-hour limit gives committed runners real room to finish, but the altitude makes it a tougher debut than a sea-level race. If you live down low, the thin air alone will slow you on the climbs. Train the vert, get time on technical and exposed trail, and rehearse your fueling and hydration before race day. If you want to ease in, the 15 mile is a great way to see the trails and the climbing before committing to a fifty.

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