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⏵ Course guide · Colorado ultra

Mace’s Hideout 100 Course Guide

Mace’s Hideout is an old-school, low-key hundred (and fifty) in the Wet Mountains west of Pueblo, Colorado, run out of Pueblo Mountain Park near Beulah. It is about 101 miles with roughly 22,500 feet of climbing at altitude, and it sends you up to the Greenhorn crest, down into hot dry high desert, back up, along the ridge, and home down a canyon. You get desert heat by day and some of the coldest, darkest, most star-filled nights in Colorado up high. I will walk you through the course, then give you pacing, fueling, night, and crew strategy built for exactly that, with free tools to dial in your own numbers.

⏵ At a glance

Mace’s Hideout 100 quick facts

Date
June 6 to 7, 2026 (Saturday start)
Location
Wet Mountains, start/finish at Pueblo Mountain Park near Beulah, about 20 mi west of Pueblo, CO
Distances
100 miler (about 101 mi) and 50 miler
Elevation gain
100M: about 22,500 ft of climb · high point about 11,659 ft, low about 6,608 ft, average about 9,058 ft
Start
8:00 AM (both distances)
Cutoff
100M: 36 hr (ends 8 PM Sun) · 50M: 16 hr (ends midnight) · 5 PM cutoff at Second Mace before the finish
Aid / field
100M: 11 aid stations · 50M: 4 · roughly 75 spots per distance
Qualifier
No Western States, Hardrock, or UTMB Running Stones status listed by the race

These facts come from the official race site and UltraSignup. The field is small and fills fast, and the date, exact route, cutoffs, and aid stations can change year to year, so confirm the current specifics in the race-day details before you commit.

The course: where Mace’s Hideout is won and lost

The 100 miler is a big loop with some out-and-back to it, starting and finishing at Pueblo Mountain Park near Beulah. About 101 miles, roughly 22,500 feet of climbing, 11 aid stations, and an average elevation around 9,058 feet. Around 60 percent of it is trail, with the rest on 4x4 and dirt road, and the route splits the Wet Mountains into two completely different worlds: the wet, forested east side and the dry, sun-baked west side. Where you win or lose this race is in pacing the early climb, surviving the heat in the desert, and getting through the cold dark night up high without falling apart.

The climb to the Greenhorn crest

The day opens with the long climb from Pueblo Mountain Park up to the crest of the Wet Mountains and the Greenhorn aid station. This is the patience test. You are gaining real altitude on fresh legs early in the morning, and the temptation is to climb hard because you feel good and the field is small enough that you can see who is around you. Don’t. Hike the steep pitches, hold an easy even effort, and get to the top with your legs and your stomach intact. You come back through Greenhorn later, so think of this as setting up the whole rest of the day, not racing it.

Up high the air is thin and the views open up across the range. Pace this by breathing and effort, not by your home pace. Every grade feels harder at 9,000 to 11,000 feet, and you have a very long way to go.

The high desert: the heat in the middle

From the Greenhorn crest the course drops off the dry west side into high desert, the world of piñon, juniper, yucca, and cactus, and then makes you climb back up toward Greenhorn a second time. The descending here is runnable and it is tempting to let it rip, but this is also where the heat lives. Afternoon sun in those exposed, dry sections is the thing race reports keep flagging as the real problem, more than the climbs.

Treat the desert like its own race within the race. Keep your core temperature down, drink to the heat, lean on sodium, and carry enough out of each aid station to cover the exposed gaps. Cooking yourself out here is how a strong morning turns into a long, ugly night, so back off the pace if you have to and bank patience instead of time.

The crest traverse and St. Charles Peak

After the second pass through Greenhorn the course traverses the ridge toward St. Charles Peak, the high point of the day near 11,659 feet, and on toward the upper aid stations. This is high, exposed, beautiful, and increasingly lonely as the field spreads out. For most runners this stretch lands in the cold and the dark, and the Wet Mountains get genuinely cold and windy up here at night, with some of the darkest skies in Colorado overhead.

This is where the race is survived rather than raced. Layer up before you are cold, keep eating even when your appetite is gone, and keep your feet moving. A pacer through these hours is worth a lot, both for safety and for keeping you honest about fueling and forward motion.

The canyon descent to the finish

The last act drops off the crest and works down the canyon toward the finish, with a few climbs still mixed in to remind you it is not over. There is a hard 5:00 PM cutoff at the Second Mace aid station before the run home, so you cannot dawdle on the high ridge and expect to sneak in. If you paced the climb, managed the desert heat, and stayed warm and fed through the night, you arrive here with something left and the descent is a reward. If you blew any of those, the closing miles are a slow grind.

Practice runnable downhill on tired legs before race day. Being able to keep moving downhill late, when your quads are trashed and you have been out all night at altitude, is what separates a finish from a long sit at Second Mace.

Pacing strategy for a high-altitude, hot-then-cold hundred

With about 22,500 feet of climbing, a day spent above 9,000 feet, and a swing from desert heat to a cold dark crest, Mace’s Hideout is about managing effort and temperature, not chasing a pace chart. Run it by feel and by grade, and treat the 36 hour clock as room, not a target to test.

Pace the climbs by grade, not by the watch

Your flat-ground pace is meaningless on the Greenhorn climb and the desert haul-back. What matters is grade-adjusted effort, so hold a steady output you can keep up the grade and hike the steep stuff without guilt. The altitude tax is real here all day, so what feels easy is probably still too hard early. Use a grade-adjusted pace to turn your real fitness into honest climbing and descending targets, and you will not torch the first half and pay for it on the crest at 2 AM.

Build a vert-aware, cutoff-honest finish prediction

Do not guess your Mace’s Hideout finish off a road or low-altitude time. The 22,500 feet of climbing, the thin air, the heat, and a full night all add real time. A vert-aware finish prediction that accounts for this course’s climbing gives you a realistic window, and then you can work backward into the 36 hour limit and that hard 5:00 PM Second Mace cutoff, so you know how much buffer you actually have at each point instead of hoping.

⏵ Free tools to pace this course

Fueling strategy for altitude, heat, and a long night

You are out here for the better part of a day and a night at altitude, through desert heat and a cold dark crest, with some long carries between aid. That makes carbohydrate, sodium, and fluid every bit as important as fitness.

Carbs: steady, trained, and altitude-proof

For a hundred this long, aim for around 60 to 90 grams of carbohydrate per hour, leaning to the high end early while your gut still plays along and settling to whatever you can actually keep down once the altitude and the heat blunt your appetite. Use a glucose-plus-fructose blend so you can absorb more than one sugar allows, and rehearse your exact hourly carb number on long training runs, ideally high and hot, so 80-plus grams an hour feels normal and not like a science experiment at mile 70. The mistake out here is under-fueling through the night because nothing sounds good, and then bonking on the crest.

Sodium and fluid: built for the desert and the gaps

In the hot, dry, exposed west-side sections your sweat and sodium losses climb, so bias sodium toward the high end, often around 500 to 700 milligrams per liter of fluid, and higher if you are a heavy or salty sweater. Just as important, carry enough fluid out of each of the 11 aid stations to actually reach the next one, because some of the carries are long and sun-baked and rationing to empty is how people unravel. Weigh yourself before and after a hot long run to find your real sweat rate, then build the plan around your own number instead of a generic one.

⏵ Build your fueling plan

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

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Mace’s Hideout 100 FAQ

How hard is the Mace’s Hideout 100?

It is a genuinely tough mountain hundred, and the elevation profile is the tell. The 100 miler runs about 101 miles with roughly 22,500 feet of climbing in the Wet Mountains, the high point sits near 11,659 feet, and you spend the whole day averaging over 9,000 feet, so the altitude is on you start to finish. You climb to the Greenhorn crest, drop into hot, dry high desert, climb back up, traverse the ridge past St. Charles Peak, then descend the canyon to the finish. Add a big swing from desert heat in the afternoon to cold, dark, exposed nights up high, plus a small field of around 75 runners and long lonely stretches, and you have a hard, old-school day. The 36 hour limit gives you room, but you have to keep moving.

How much climbing is in the Mace’s Hideout 100?

The 100 miler racks up about 22,500 feet of total elevation gain over roughly 101 miles, per UltraSignup and the official race. The high point is around 11,659 feet near St. Charles Peak, the low is about 6,608 feet, and the average elevation is about 9,058 feet, so you are climbing and dropping all day at altitude. The big set pieces are the climb from Pueblo Mountain Park up to the Greenhorn crest, a descent into the high desert and the haul back up to Greenhorn a second time, then a long ridge traverse before the final canyon descent to the finish. The 50 miler shares the early Wet Mountains terrain with less of the total vert.

How should I fuel for the Mace’s Hideout 100?

Plan for a long day at altitude with a real heat-then-cold swing, not a steady climate. Most hundred milers do well on roughly 60 to 90 grams of carbohydrate per hour, leaning toward the high end early when your gut still cooperates and easing to what you can actually keep down once the heat and the hours pile up. Altitude blunts your appetite, so keep the calories steady and easy to swallow instead of betting on big late doses. Sodium should ride with the heat in the dry desert sections, often the high end of 500 to 700 mg per liter of fluid, and more if you sweat salty. There are 11 aid stations on the 100, but some carries are long and exposed, so leave each one with enough food and fluid to reach the next. Run your own numbers with the free ultra fueling calculator.

What are the cutoff times for the Mace’s Hideout 100?

The 100 miler has a 36 hour overall limit, an 8:00 AM Saturday start to an 8:00 PM Sunday finish, and there is a hard 5:00 PM cutoff at the Second Mace aid station before the run to the finish. The 50 miler has a 16 hour limit and ends at midnight. With 36 hours you have margin, but the altitude, the night, and the long high-desert stretches eat into it fast if you sit too long at aid. Confirm the full intermediate cutoff schedule in the current runner info before race day, because the published times can shift year to year.

What is the terrain and weather like at Mace’s Hideout?

The course is roughly 60 percent trail with the rest on 4x4 and dirt road, so you get rocky singletrack, forest service jeep roads, and a couple of short highway connectors, all in the Wet Mountains west of Pueblo. You cross two very different worlds: the wetter east side with firs, spruce, and lodgepole pine and high alpine meadows, then the dry west side with piñon, juniper, yucca, and cactus. Weather in early June swings hard. The high-desert sections can cook in the afternoon sun, and the nights up on the crest get cold, windy, and very dark, which is part of the draw here (some of the darkest skies and best stars in Colorado). Pack for both ends of that range.

Do I need a crew and pacer for the Mace’s Hideout 100?

You do not strictly need them, but on a remote high-altitude hundred with a small field and long lonely stretches, a crew and a pacer help a lot. Drop bags are allowed at several aid stations on the 100 (Greenhorn, Pole Creek, Sand Hollow, and Second Mace), so even solo runners can stash warm layers, a headlamp and spare batteries, night calories, and dry socks at the right points. Note that some aid stations take real time to reach by road, so a crew has to plan their driving carefully and you should not count on seeing them everywhere. A pacer through the cold dark crest hours is worth a lot for safety and for keeping you eating and moving. Check the current crew, pacer, and drop-bag rules with the race before you build your plan.

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.