⏵ Course guide · West Texas mountain ultra
Sky Island climbs 3,901 feet through the Davis Mountains, one of only three true "sky islands" in Texas, a cooler, wetter range rising out of the surrounding high desert near Fort Davis. The course threads singletrack past Prude Ranch, up the steep Indian Lodge climb, and along the Old CCC trail with views of Fort Davis and the McDonald Observatories. I will walk you through the terrain first, then give you a pacing and fueling plan built for real mountain climbing, not the flat Texas most runners expect. Free calculators along the way to dial in your own numbers.
These facts come from the official RunSignup registration page and the race's own course page. Race logistics change year to year, so confirm the current specifics before you commit.
The Davis Mountains form one of only three unique sky islands in Texas, a cooler, wetter landscape surrounded by arid lowland desert. The 50K starts and finishes at Prude Ranch, adjacent to the range, and gains 3,901 feet over the loop.
The 50K opens with 800 feet of climbing over the first 5 miles, then flattens for a couple of miles before dropping down into Sheep Pens Gulch. From there the course crosses under the highway and enters Davis Mountains State Park proper, where the real climbing begins.
The Montezuma Quail Trail leads up to the Indian Lodge climb, the steepest stretch on the whole course. You run to the top and drop down behind Indian Lodge itself, cut through its parking lot, and follow the park road briefly before turning onto Skyline Drive and connecting to the Old CCC trail entrance.
From the Old CCC trail the course climbs to Skyline, then makes a loop through Fort Davis, past its old historic buildings, before returning down the Skyline trail. Runners retrace their steps back under the highway and through the Primitive loop the same way they started, closing the loop back at Prude Ranch.
Aid comes from the Park Entrance, Skyline, and Primitive stations. The 50K can stage a drop bag at Park Entrance (the 25K and 10 Mile cannot), and spectators can access Park Entrance, Camp, and Skyline aid stations by vehicle, though Skyline requires a short, rocky 150-meter hike in on foot.
With an 11-hour window for the 50K, you have room to respect the Indian Lodge climb and the steep sections of Old CCC trail without racing the clock from the start.
The first 5 miles bring 800 feet of gain right out of the gate, before you have settled into the day. A grade-adjusted pace target for that early climb keeps you from burning matches you will want later on the Indian Lodge climb, which is the steepest section on the course and comes with real fatigue already in your legs.
With 3,901 feet of gain packed into 31 miles, a flat-course pace estimate will mislead you badly. A vert-aware finish prediction gives a far more honest number, and checking it against the 4:30 PM cutoff after the Indian Lodge climb tells you whether you have room to enjoy the Fort Davis overlooks or need to pick up effort on the way back.
⏵ Free tools to pace this course
A 5:30 AM start means cool early miles, but the exposed Skyline sections warm up fast once the West Texas sun is up over the high desert.
Aim for roughly 60 to 90 grams of carbohydrate per hour, and use the Park Entrance, Skyline, and Primitive stations to keep your intake consistent through the climbing sections where fueling is easy to neglect. The 50K's Park Entrance drop bag option is worth using for exactly the fuel you know you'll want by then.
Sodium in the 300 to 700 mg per liter range covers most runners, leaning toward the lower end for the cool early miles through Sheep Pens Gulch and higher once you are climbing exposed sections like Old CCC trail and Skyline later in the morning.
⏵ Build your fueling plan
Get a carb, sodium, fluid, and caffeine plan per hour built for your weight, your goal time, and a high-desert West Texas day 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 and this exact 3,901-foot Davis Mountains profile. Summit Line reads your real training, builds the climbing legs the Indian Lodge and Old CCC trail sections demand, and rehearses your fueling so race day is something you execute, not guess at.
Both the 50K and 25K carry the race's own "Very Hard" rating, and the numbers back it up: the 50K packs 3,901 feet of gain into just over 31 miles, with the steepest section coming at the Indian Lodge climb after you have already banked 5 miles and 800 feet on the way in. This is genuine mountain terrain in a state most runners do not associate with real vert, and the Davis Mountains do not go easy on you just because you did not expect them to.
The 50K gains 3,901 feet over its actual 31.1 miles. The first 5 miles bring 800 feet of climbing, then the course flattens briefly before dropping into Sheep Pens Gulch, crossing under the highway, and entering Davis Mountains State Park. From there the Montezuma Quail Trail leads to the steepest section of the day, the Indian Lodge climb, before the course threads through Old CCC trail up to Skyline, loops past Fort Davis's historic buildings, and retraces back to the finish.
A 5:30 AM start in the high West Texas desert means cool early miles that warm up fast once the sun is up over exposed Skyline sections. Aim for roughly 60 to 90 grams of carbohydrate per hour, and keep sodium in the 300 to 700 mg per liter range, leaning higher as the day heats up. Aid comes from three stations, Park Entrance, Skyline, and Primitive, and the 50K can stage a drop bag at Park Entrance, so plan your specific race-day fuel around that access rather than carrying everything from the start. Build your numbers with the free ultra fueling calculator before race day.
The 50K runs from 5:30 AM to a 4:30 PM cutoff, an 11-hour window for 31.1 miles and 3,901 feet of climbing. The 25K gets 7:30 AM to 2:30 PM (7 hours), and the 10 Mile gets 8:30 AM to 2:30 PM (6 hours). Given the "Very Hard" rating on both the 50K and 25K, respect those windows, especially through the steep, technical Indian Lodge and Old CCC trail sections.
Only if you already have real mountain trail experience. The "Very Hard" rating and nearly 3,900 feet of gain make this a demanding course for a first ultra, closer to a mountain 50K than a typical flat or rolling one. If you have trained on steep, technical climbs and descents and you want a genuinely scenic West Texas mountain challenge with views of Fort Davis, McDonald Observatories, and Indian Lodge, the 11-hour cutoff gives a well-prepared runner real room to finish.
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<a href="https://runsummitline.com/guides/sky-island-50k">The Sky Island course guide</a><iframe src="https://runsummitline.com/embed/race/sky-island-50k" style="width:100%;max-width:420px;height:180px;border:0;" loading="lazy" title="Sky Island course guide by Summit Line"></iframe>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.
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