Summit Line

⏵ Course guide · Texas ultra

Pandora’s Box of Rox Course Guide

Pandora’s Box of Rox is a Tejas Trails spring ultra at Reveille Peak Ranch out near Burnet, Texas, and the name tells you the whole story: it is rocky granite, over and around one of the biggest domes in the Hill Country. The climbing is gentle, but the footing, the heat, and the four-lap grind of the 52.4 are what make it hard. I will walk you through the loop first, then give you a pacing and fueling plan that fits the rock and the Texas sun. There are free calculators along the way to dial in your own numbers.

⏵ At a glance

Pandora’s Box of Rox quick facts

Date
Saturday, April 25, 2026 (Tejas Trails runs it each spring)
Location
Reveille Peak Ranch, Burnet, TX, in the Llano Uplift of the Texas Hill Country
Distances
52.4 mi (double marathon), 26.2 mi, 13.1 mi, 8 mi, 4 mi, and a youth 1 mi
Format
A 13.1-mile granite loop: the 52.4 is four laps, the 26.2 is two, the 13.1 is one
Elevation gain
Modest by ultra standards, roughly 400 to 450 ft of rolling granite per 13.1-mile lap
52.4 start
6:00 AM CDT mass start (shorter distances start later)
Cutoff
Final lap cutoff 6:00 PM (you must be on your last lap), course closes 10:00 PM, with aid-station cutoffs along the way
Qualifier
No Western States, UTMB, or Hardrock qualifier status listed by the race

These facts come from the official Tejas Trails race page and ultra calendars. Check the current date, start times, cutoffs, and aid stations in the race-day details before you commit. Race logistics change year to year.

The course: where Pandora’s Box of Rox is won and lost

Everything here is built on one 13.1-mile loop through the granite of Reveille Peak Ranch. The 52.4 runs it four times, the marathon twice, the half once. Per lap you get rolling granite domes, single-track through meadows, creek crossings, hill country forest, and a pass by the lake, with the Lake aid station as your home base at the start/finish every time around.

The granite: this is a footing race, not a climbing race

Do not let the gentle elevation profile fool you. The hard part of this course is the rock. You spend real time on exposed granite slab and rocky single-track, and that pounds your feet and your stability in a way that flat miles never do. Wear shoes with genuine rock protection and a grippy outsole, because slick granite plus tired legs is how people roll an ankle late.

The smart move is to run the runnable, smooth meadow and forest stretches with intent and back off and pick your feet up cleanly through the rocky sections. Trying to hammer the technical granite to save thirty seconds is a great way to go down hard on lap three. Quick, attentive feet beat raw aggression here every single time.

The laps: your biggest weapon and your biggest trap

The loop format is a gift if you use it. You pass the Lake aid station and your drop bag every 13.1 miles, so you can restock fluid and calories, swap a bottle, grab ice, and reset on a fixed rhythm. Treat each lap like its own little race with a plan for what you do at the aid station, and the day gets a lot more manageable.

The trap is mental. Running back through the start/finish and then turning around to head out for another full lap is hard, especially on lap three of the 52.4 when the easy distances are already done and shade is thin. Decide before the race that you are going to keep moving through that aid station, not sit down in it, and the laps stop owning you.

Heat and exposure on the dome

Late April in central Texas is a coin flip. You might get a cool, soft morning, or you might get warm and humid by mid-day, and the open granite holds and throws heat back at you with very little tree cover up on the dome. The aid stations carry ice for a reason, so use it: ice in a bandana, ice down your front, cold fluid every loop.

Plan for the heat from the first lap instead of reacting to it when you are already cooked. Start your fluid and sodium early, keep eating before your stomach shuts down in the warmth, and use the drop-bag access along the loop to keep something cold within reach. The runners who manage the temperature are the ones still moving well on the last lap.

Pacing strategy for a rocky, multi-lap Texas ultra

With gentle climbing and a repeating 13.1-mile loop, Pandora’s is about even effort and discipline, not chasing a pace chart over big mountains. The goal is to run lap four at close to the effort you ran lap one, which means starting more conservatively than feels natural.

Run the first lap slower than you want to

The classic blow-up here is feeling fresh and fast on lap one in the cool morning, banking time, and then falling apart when the heat builds and the rock adds up. Negative-split thinking wins this race. Hold back early, keep the technical sections smooth, and let the people who went out hot come back to you on the back half. Your flat-ground pace will not survive the granite, so run by effort and let the surface set your speed.

Build a realistic finish window and work back into the cutoffs

Do not predict your Pandora’s finish off a road marathon time. The rocky footing and the heat add real minutes per mile, even with modest climbing, so a vert-aware and surface-aware estimate keeps you honest. Build a realistic finish window, then work backward into the 6:00 PM final lap cutoff and the aid-station cutoffs so you know exactly how much buffer you have at the end of each lap instead of guessing out on course.

⏵ Free tools to pace this course

Fueling strategy for the heat and the long day

The 52.4 is a long day, often well into double-digit hours for mid-pack runners, and the central Texas warmth makes carbohydrate, sodium, and fluid every bit as important as fitness. The good news is the loop puts your drop bag in front of you every 13.1 miles.

Carbs: steady, trained, and easy to get down in the heat

For a long ultra effort, aim for around 60 to 90 grams of carbohydrate per hour, and only push the top end if your gut is trained for it. Heat kills your appetite and slows your stomach, so keep your intake steady and reach for things that go down easy when it is warm. Practice your exact race-day carb rate on hot long runs so 80-plus grams an hour feels normal on lap three, not like an experiment you are running mid-race.

Sodium and fluid: lean high and restock every lap

In central Texas warmth, lean toward the high end on sodium, often around 500 to 700 milligrams per liter of fluid, and more if you are a heavy or salty sweater. Use the lap format to your advantage: top off fluid and grab ice at the Lake aid station every 13.1 miles, and keep something cold in your drop bag at the gate access on the loop. Weigh yourself before and after a warm 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 Pandora’s heat 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 Pandora’s Box of Rox loop, and your projected lap splits. Summit Line reads your real training, builds a plan for the rocky footing and the heat, and rehearses your fueling so race day is something you execute, not guess at.

Start free →Explore the demo

Pandora’s Box of Rox FAQ

How hard is Pandora’s Box of Rox?

It is harder than the climbing numbers make it look. The vert is modest for an ultra, but the name is the warning: the course is genuinely rocky granite, so the difficulty comes from the footing, the heat, and the repetition of running the same 13.1-mile loop multiple times. The 52.4 is four laps of that loop, which is as much a mental test as a physical one. Honest footwork, smart pacing, and a heat plan matter way more here than raw speed.

How much climbing is in Pandora’s Box of Rox?

Reveille Peak Ranch is rolling Hill Country, not big mountains, so the climbing is on the gentle side for an ultra. Each 13.1-mile loop carries roughly 400 to 450 feet of gain over granite domes and meadows, which puts the 52.4-mile double marathon somewhere in the neighborhood of 1,700 to 1,900 feet total. The race does not publish an official per-distance vert number, so treat that as a planning estimate and confirm with the current course data. The real load on your legs is the rocky surface, not the elevation.

What is the lap format at Pandora’s Box of Rox?

It is a looped course built around a 13.1-mile lap through Reveille Peak Ranch. The half marathon is one lap, the marathon is two laps, and the 52.4-mile double marathon is four laps, with the start/finish aid station (the Lake aid station) anchoring every lap. The upside is huge: you can stash a drop bag, restock every loop, and break the day into bite-sized pieces. The downside is the mental side of passing the finish line and heading back out for another lap.

What are the cutoff times for Pandora’s Box of Rox?

For the long course there is a final lap cutoff at 6:00 PM, meaning you must already be out on your last lap by then, and the course closes at 10:00 PM. There are also intermediate aid-station cutoffs along the loop, and missing one means you were already too slow to finish in time. Because the 52.4 starts at 6:00 AM, that gives you a generous overall window, but you still cannot bank all your buffer for the end. Check the current aid-station cutoff chart before race day.

What is the terrain and weather like at Pandora’s Box of Rox?

The course runs over and around one of the largest granite domes in the region, mixing exposed slabs with single-track through meadows, hill country forest, creek crossings, and a lake. The footing is rocky in stretches, hence the name, so this is a place to wear shoes with real rock protection and to watch your feet when you get tired. Late April in central Texas can swing from cool and pleasant to genuinely warm and humid, and the granite holds heat, so plan for sun and treat the temperature as a real variable.

Is Pandora’s Box of Rox a good first ultra or first 50?

The 52.4 makes a strong first big day because the lap format is forgiving: you are never far from your drop bag, you can bail to a shorter finish if the day falls apart, and the climbing is gentle. The challenges to respect are the rocky footing, the central Texas heat, and the head game of running the same loop four times. If you train on rocky trail, rehearse fueling and hydration in warm weather, and go in with a plan to break the race into laps, most prepared runners have the time to finish inside the cutoffs.

This guide is independent and for planning only. The course details, dates, start times, 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.