⏵ Course guide · New Mexico backcountry hundred
The Gila 100 and 50 run out-and-back from Open Space Brewing through historic Fort Bayard and onto the Continental Divide Trail in the Gila National Forest near Silver City, New Mexico. Roughly 7,387 feet of climbing for the 50, doubled for the 100. I will walk you through the 2026 course format and terrain first, then give you a pacing and fueling plan built for a remote, out-and-back backcountry hundred, plus free tools to dial in your own numbers.
These facts come from the official Gila Adventure Runs race page. The course format changed for 2026, check the current year details, cutoffs, and aid stations before you commit.
For 2026, the 100 Mile shifted from a single out-and-back to running the same 50-mile out-and-back course twice, a change made for better support, safety, and accuracy while keeping the total distance and challenge the same.
From the start at Open Space Brewing, the route heads through Bataan Park and historic Fort Bayard on fast dirt, then climbs steep and technical toward Twin Sisters and up onto the Continental Divide Trail (CDT). From there it follows a forested ridge, descending toward the Mimbres Valley before dropping to the Sapillo Campground turnaround, the halfway point for both distances.
The 100-mile runner completes the same out-and-back twice: back to start/finish, then out and back again. Your first pacer can join at the start/finish (the 50-mile finish point), and a second pacer can join on your second pass through Sapillo. If you decide to drop to the 50-mile distance, you must do it at the start/finish, the halfway point, not later on course.
Some aid stations sit in extremely remote spots where crew and pacers are not allowed, for safety. The course is heavily marked, including reflective elements, since much of the 100-mile field will be navigating parts of it in the dark on the second pass.
The official race notes state a 24-hour pace of 13:20 per mile and a 36-hour pace of 20:00 per mile, useful reference points for setting your own target against the terrain.
A grade-adjusted pace target for the steep, technical Twin Sisters climb and the rolling CDT ridge gives you a more honest number than flat pace. Because it is an out-and-back, your outbound split to Sapillo is a direct preview of what the return trip demands, so use it to plan effort rather than hoping the way back feels easier.
Because the 100-mile course repeats the exact 50-mile route, your first pass is real data for your second. A vert-aware finish prediction built off your first-half splits, checked against the per-aid-station cutoffs, tells you honestly whether to hold pace or ease off before starting your second out-and-back.
⏵ Free tools to pace this course
Mid-October in the Gila high country swings from warm daytime temperatures to cold nights, especially climbing toward the Continental Divide, so plan your fueling to shift with the clock.
Aim for roughly 60 to 90 grams of carbohydrate per hour. Every aid station carries water and Hammer Nutrition products plus volunteer home-cooked meals, a real advantage on a remote course, but some stations do not allow crew or pacer access, so pack enough to cover the gaps confidently rather than relying on a crew handoff that is not available at every stop.
Sodium in the 300 to 700 mg per liter range covers most of the day, leaning higher during warm daytime climbing. For the overnight sections, especially on your second pass if you are running the 100, pack real layers, mountain nights in the Gila high country get cold even after a warm day.
⏵ Build your fueling plan
Get a carb, sodium, fluid, and caffeine plan per hour built for your weight, your goal time, and a warm day into a cold Gila high-country night 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 Gila out-and-back elevation profile, and your projected splits. Summit Line reads your real training, builds a plan for a remote backcountry hundred, and rehearses your fueling so race day is something you execute, not guess at.
The Gila 100 climbs roughly 14,774 feet over an out-and-back course through the Gila National Forest's high country near Silver City, New Mexico, following the same 50-mile route twice. That is New Mexico's only 100-mile trail race, remote and rugged, following historic corridors and Continental Divide Trail singletrack. The 36-hour cutoff is generous by 100-mile standards, but the terrain and remoteness (some aid stations do not allow crew or pacers) make this a serious backcountry test.
The official course page publishes roughly 7,387 feet of climbing for the 50 Mile (and the same in descent, for about 14,774 feet of total elevation change on the out-and-back). The 100 Mile doubles that: roughly 14,774 feet of climbing and about 29,548 feet of total elevation change, since it runs the same 50-mile out-and-back course twice.
Mid-October in the Gila high country can run warm by day and cool at night, especially once you are climbing toward the Continental Divide. Aim for roughly 60 to 90 grams of carbohydrate per hour and sodium in the 300 to 700 mg per liter range. Every aid station stocks water and Hammer Nutrition products, plus volunteer home-cooked meals, so you can supplement what you carry, but some aid stations are remote with no crew or pacer access, so plan your self-sufficiency between those stretches. Build your numbers with the free ultra fueling calculator before race day.
Both the 100 Mile and 50 Mile carry a 36-hour overall cutoff, with specific cutoffs published at each aid station along the way (for example, the 50-mile turnaround at Sapillo closes at 10:00 PM Saturday, and the finish closes at 6:00 PM Sunday). At a stated 24-hour pace of 13:20 per mile and a 36-hour pace of 20:00 per mile, the race gives you real room to move conservatively through the remote middle sections.
The course runs out-and-back from Open Space Brewing through Bataan Park and historic Fort Bayard, then climbs a steep, technical stretch toward Twin Sisters and onto the Continental Divide Trail, following a forested ridge before dropping toward the Mimbres Valley and the Sapillo Campground turnaround. Expect historic corridors, runnable dirt, and genuine high-country trail, heavily marked with reflective elements for the overnight return.
The 2026 course change, running the 50-mile out-and-back twice for the 100 rather than a single longer route, was made specifically to improve runner safety, support, and accuracy, and it means 100-mile runners get to use their knowledge of the first half to pace the second, plus the option to drop to the 50-mile distance at the halfway point if the course proves harder than expected. Combined with a 36-hour cutoff and heavily stocked aid stations, that makes Gila a more forgiving first-100 option than many remote backcountry hundreds, as long as you respect the genuine remoteness of some sections.
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<a href="https://runsummitline.com/guides/gila-100-50">The Gila 100/50 course guide</a><iframe src="https://runsummitline.com/embed/race/gila-100-50" style="width:100%;max-width:420px;height:180px;border:0;" loading="lazy" title="Gila 100/50 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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