Ouray 100 Course Guide

The front 50: jeep-road climbs to Fort Peabody

The early miles head up Camp Bird Road and Imogene Pass Road toward Fort Peabody, the high point of the day near 13,340 feet. A lot of this is on jeep road, which sounds friendly until you realize you are gaining thousands of feet at altitude, often in the heat of the afternoon on day one. This is not the place to feel strong and push. The smart move is to hike the steep grades efficiently, keep your effort honest, and treat the front half as setup for a race that is decided much later.

Up high you are exposed, and that matters here as much as the grade does. You spend real time above treeline tagging passes and peaks, and the San Juans in July serve up afternoon thunderstorms with hail and lightning almost daily. Have a plan for the high sections, watch the sky, and do not get caught dawdling on an exposed pass when the weather turns.

The back 50: steeper trail, the night, and the lows

The back half of the course trades jeep road for steeper, mostly dirt alpine trail, and this is where the race gets technical and slow. It is also where the 50 mile race runs its loop. By now you are deep into the night, your legs are full of descent, the altitude has been working on your stomach for hours, and the lows come hard. Almost everyone who runs Ouray goes through a dark patch out here in the small hours. Expect it, eat through it, keep moving, and know that it passes.

The descents are the quiet quad-killer on this course. Fourteen climbs means fourteen descents, much of it steep and rocky, and if you bombed the early downhills your legs are wrecked long before the finish. Run the descents controlled and light from the very start so you still have something for the climbing that never stops.

The Bridge of Heaven and the drop into town

The course saves a gut-punch for last: a roughly 5,000 foot climb up the Old Horsethief Trail to the Bridge of Heaven, then the long descent back down to Fellin Park and the finish. Climbing 5,000 feet at mile 90-something, on no sleep and trashed legs, is exactly as hard as it sounds, and it is where the race makes you prove you want the buckle.

The good news is the finish is genuinely special. You drop back into Ouray and end yards from the hot springs, which is about the best reward a 100 mile day can offer. Get there with enough left to enjoy the last descent instead of surviving it, and that means pacing the first 90 miles like the back-loaded course it is.

Aid stations, crew, and drop bags

The aid stations are well stocked for a race this remote. The bigger ones, like Ironton and the Fellin Park area you pass through more than once, carry hot food such as soup, ramen, grilled cheese, and quesadillas, alongside the usual fruit, salty snacks, sweet snacks, water, and sports drink. A couple of the earlier or more remote stops are lighter or water-only, so do not assume every stop is a full kitchen. Carry enough to cover the longer gaps between them.

A crew is a real advantage on a course this long and this hard, both to feed you and to drag your head out of the late-race hole. The start-finish at Fellin Park plus the bigger aid points give a crew places to reach you. Confirm the current pacer rules, drop-bag locations, and crew-access points in the official race materials before race week, because those details get set per edition and you do not want to guess.

Pace the climbs by grade and effort, not the watch

Your flat-ground pace is meaningless on the Ouray climbs, and at altitude it is worse than meaningless. What matters is grade-adjusted effort: hold an output you can sustain up the grade, hike the steep pitches without guilt, and let the watch tell you about effort instead of speed. The classic blowup here is pushing the front-50 jeep-road climbs because they look runnable, then falling apart on the steeper back half. Use a grade-adjusted pace to turn your real fitness into honest climbing and descending targets so you do not torch the first day.

Then bake the altitude into your expectations. Everything above 12,000 feet feels harder than the same grade at home, so your climbing pace up high will be slower and your heart rate higher, and that is normal. Plan to power-hike a lot of this course. The strongest Ouray runners are efficient hikers, not just fast runners.

Protect your quads across fourteen descents

Fourteen climbs means fourteen descents, much of it steep and rocky, so downhill durability is a defining skill here, not an afterthought. Run the early and middle descents controlled and light instead of letting gravity hammer your legs, because the back half and that final climb to the Bridge of Heaven both demand legs you still own. Trash your quads on the front-50 downhills and the last 30 miles turn into a shuffle.

Use the grade-adjusted pace calculator to check whether you are descending sustainably or cashing in legs you will want at mile 80. With a 52 hour clock there is no prize for fast early descents, only a penalty for them.

Build a vert-aware finish goal against the 52 hour clock

Do not guess your Ouray finish off a road or even a flatter trail 100. The 41,862 feet of climbing, the altitude, the technical back half, and two nights out there all add huge amounts of time. A vert-aware finish prediction that accounts for this much gain gives you a realistic window, and then you can work backward into the cutoffs so you actually know how much buffer you have, rather than hoping. With a generous limit, the goal for most runners is simply to keep moving and bank margin early against the day-two lows.

Carbs: steady, swallowable, and trained

For an effort this long, target roughly 60 to 90 grams of carbohydrate per hour, and lean to the lower-middle of that band, especially early and up high where altitude shuts your stomach down. The goal is a steady, easy-to-swallow drip rather than big doses you choke on, and a glucose-plus-fructose blend helps you absorb more without trashing your gut. Rehearse your hourly carb number on long climbs in training so it feels routine, not like an experiment at 12,000 feet.

Lean on the aid stations for real food when gels stop going down. The bigger Ouray stops carry hot soup, ramen, grilled cheese, and quesadillas, and a few hundred warm calories in the cold night can reset a stomach that has quit on sugar. Keep eating through the lows even when you do not want to, because the engine still needs fuel long after your appetite checks out.

Sodium, fluid, and the cold nights

Set your sodium to your own sweat, generally somewhere in the 300 to 700 mg per liter of fluid range, higher if you run salty, and carry enough fluid to cover the longer gaps between aid rather than rationing to the next stop. Up at altitude you also breathe off more water than you think and the dry air hides it, so keep drinking on a schedule even when it is cold and you do not feel thirsty.

And it does get cold. Two nights above treeline in the San Juans get genuinely frigid, so warm fuel, warm layers, and staying on top of calories all work together to keep you from spiraling when your core temperature drops. Weigh yourself before and after a long mountain effort to find your real sweat rate, then build the plan around your own number.