⏵ Course guide · Remote West Texas desert ultra
The Big Bend Ultra runs 10K to 100K through Big Bend Ranch State Park, over 300,000 acres of remote Texas desert with zero cell service and a Gold Tier Dark Sky certification. I will walk you through what makes this course genuinely isolated first, then give you a pacing and fueling plan built for self-sufficient desert running, plus free tools to dial in your own numbers.
These facts come from the official Trail Roots race page. Check the current year details, cutoffs, and aid station access before you commit. Race logistics change year to year.
All distances start and finish at the Barton Warnock Visitor Center in Big Bend Ranch State Park. The 10K is an out-and-back with no aid station (the only distance the course vehicle cannot support), while the longer distances run through genuinely remote backcountry.
Race organizers cap the 100K at 100 participants and enforce a strict 20 hour cutoff, both explicit acknowledgments of how hard this course is to support. The official page notes plans to extend the cutoff as the race grows, but for now, budget your day around a hard 20 hour limit rather than a generous one.
The Contrabando aid station is the only one accessible by vehicle to spectators. Every other aid station on course has no crew or spectator access and no cell service, staffed only by designated volunteers. Plan your race assuming you are on your own between stops, not counting on a crew meeting you at every aid station.
The International Dark-Sky Association has certified the Big Bend Ultra race area as a Gold Tier Dark Sky Park, the highest level of recognition. If your race extends into the night on the 55K or 100K, you are running under some of the darkest, clearest skies available anywhere in Texas.
With no pacers allowed and aid stations spread across truly remote terrain, your pacing plan needs to build in real margin rather than assume you can problem-solve on the fly with help.
A "hard" cX rating on the 100K and 55K means the course itself, not just its length, slows you down. Use a grade-adjusted pace target rather than a flat-ground number, since the official difficulty ratings suggest sustained technical or exposed terrain rather than a runnable, fast course.
A vert-aware finish prediction gives you a more honest number than assuming average ultra pace, especially on a course this remote. Check that projection against the 100K's hard 20 hour cutoff early in your training block, not on race morning, since there is no flexibility built into this cutoff.
⏵ Free tools to pace this course
Mid-January in the Big Bend desert can swing from cold overnight temperatures to warm daytime sun, and with remote, widely-spaced aid, your carry capacity matters as much as your per-hour targets.
Aim for roughly 60 to 90 grams of carbohydrate per hour on the 55K and 100K. Because most aid stations have no crew or spectator vehicle access, plan to carry more food and fluid between stops than you would on a typical, more accessible ultra course, and use your drop bags strategically at whichever aid points allow them.
Sodium in the 300 to 700 mg per liter range covers most runners, leaning toward the higher end for exposed, sun-baked stretches of the course. Desert conditions can dehydrate you faster than you expect even in January, so do not assume cooler winter temperatures eliminate the need for real sodium and fluid planning.
⏵ Build your fueling plan
Get a carb, sodium, fluid, and caffeine plan per hour built for your weight, your goal time, and a remote West Texas desert 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, this exact remote desert course profile, and your projected splits. Summit Line reads your real training, builds a plan for self-supported ultra distance, and rehearses your fueling so race day is something you execute, not guess at.
The official course ratings call the 100K and 55K "hard," the 35K and 20K "moderate," and the 10K "easy." Beyond the terrain itself, the remoteness is what defines this race: over 300,000 acres of Big Bend National and State Parks, zero cell service on course, and aid stations that are inaccessible to crew or spectators by vehicle. This is a race that demands self-sufficiency as much as fitness.
Trail Roots does not publish a specific elevation gain figure for any distance. Instead, each distance carries an official difficulty rating (their "cX Rating"): the 100K and 55K are rated hard, the 35K and 20K moderate, and the 10K easy. If you want an exact vert number, it is not published on the official race page, so plan around the qualitative difficulty rating instead.
Aid stations here are remote with no crew or spectator vehicle access except at the Contrabando station, and the 10K has no aid station at all (it is an out-and-back). Plan to carry more than you would on a typical ultra between stops. Aim for roughly 60 to 90 grams of carbohydrate per hour on the 55K and 100K, and sodium in the 300 to 700 mg per liter range given the exposed, remote desert terrain. All finishers except the shortest distance receive a post-race meal, and your bib doubles as your meal ticket, so do not lose it. Build your numbers with the free ultra fueling calculator before race day.
The 100K carries a strict 20 hour cutoff and is capped at 100 participants, both explicitly tied to the remoteness of the course. The official race page notes the organizers hope to extend the cutoff in future years as the race grows, but for now, 20 hours is a hard limit, not a soft target.
No. Pacers are not allowed at any distance, due to the remoteness and logistical constraints of the race. Plan to run the full distance solo, and make sure your drop bag and aid strategy account for the fact that you will not have outside company to help manage pace or morale late in the race.
Only if you are comfortable with genuine remoteness: no cell service, no pacers, and aid stations largely inaccessible to crew. The moderate-rated 35K or 20K are better entry points into this course if you have not raced in truly isolated terrain before. For an experienced ultra runner seeking a bucket-list, dark-sky desert 100K, this is one of the most distinctive courses in Texas.
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<a href="https://runsummitline.com/guides/big-bend-ultra">The Big Bend Ultra course guide</a><iframe src="https://runsummitline.com/embed/race/big-bend-ultra" style="width:100%;max-width:420px;height:180px;border:0;" loading="lazy" title="Big Bend Ultra 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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