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Umstead 100 Mile Endurance Run Course Guide

The Umstead 100 is the East Coast’s classic first hundred, a looped 100 miler in William B. Umstead State Park outside Raleigh that has been helping runners make the jump from 50 to 100 miles since the 1990s. The trail is smooth, the climbs are gentle, and you come back through the start-finish after every 12.5 mile loop. That makes it approachable, but it does not make it a gimme: eight laps, a long night, and a 30 hour clock are their own kind of test. I will walk you through the loop first, then give you pacing and fueling built for the repetition and the night, with free tools to dial in your own numbers.

⏵ At a glance

Umstead 100 quick facts

Date
Late March into early April (one Saturday; confirm the current year)
Location
William B. Umstead State Park, Raleigh, North Carolina
Distances
100 mile (eight 12.5 mile loops) and 50 mile (four loops)
Elevation gain
About 8,000 ft over 100 miles, roughly 1,000 ft per loop, gentle and rolling
Start
6:30 AM Saturday
Cutoff
30 hr overall (ends 12:30 PM Sun) · 26 hr soft cutoff (8:30 AM Sun) to start loop 8
Surface
Packed powdered-granite bridle path, 8 to 15 ft wide, excellent footing
Qualifier
A 100 mile finish counts as a Western States qualifier (over the 100k minimum)

These facts come from the official race site, its published schedule, and UltraSignup. The exact date moves around the calendar, and cutoffs and logistics can change, so confirm the current year’s details with the race before you commit.

The course: where Umstead is won and lost

Umstead is a 12.5 mile loop you run eight times for the 100, four for the 50. The surface is packed powdered-granite bridle path, 8 to 15 feet wide with excellent footing, and the climbing is gentle, only about 1,000 feet a loop in well-spaced rolling hills. There is nothing technical out there. This race is decided by how you pace the early loops, how you handle the night, and whether the repetition gets in your head.

The loop: smooth, runnable, and a pacing trap

Because the footing is so good and the hills are so gentle, you can run almost all of this course, and that is exactly the problem. The first couple of loops feel easy, your legs are fresh, the bridle path begs you to roll, and it is the simplest thing in the world to bank time you think you will need later. Resist it. The runners who finish strong at Umstead treat the early loops as a warm-up they are deliberately holding back on, hiking the gentle grades they could easily run and saving the legs for loop 6, 7, and 8.

You will learn the loop intimately, and that cuts both ways. The handful of longer grades become familiar landmarks, which helps you meter your effort, but the sameness also wears on you. Break the race into loops, not miles. Eight times around a course you know cold is a very different mental game than one long point-to-point, and the people who plan for that do better than the people who get surprised by it.

The start-finish: crew, drop bags, and resets

The single biggest gift of this course is that you pass the start-finish at Camp Lapihio after every loop. Your crew sees you eight times. That means you can carry light, reset your bottles and your nutrition every 12.5 miles, swap a headlamp, change socks, and get a quick gut check from someone who knows you. Use it. Plan each loop as a leg between crew stops, decide ahead of time what you grab each time, and keep the stops short so they do not quietly eat an hour over the day.

Aid on the loop is generous too. There are three fluid stops per loop, so you are never more than about 3.8 miles from water and support, which makes Umstead far more forgiving than a remote mountain 100 with long dry gaps. You still want to carry fluid and calories, but you are never out there alone for long.

The night and the late loops

The race starts at 6:30 AM and most runners are out there well past dark, so the back half of Umstead happens at night. Pacers are allowed from 6:30 PM, or the start of your fifth lap if you reach it earlier, and a good pacer for the night loops is worth a lot here, both for safety and for company on a course that can feel lonely in the dark. Get your headlamp and a backup sorted, plan a warm layer for the cold hours, and know that the temperature can swing a fair amount overnight in the North Carolina spring.

Loops 6 through 8 are where the race actually gets decided. If you paced the early miles honestly, kept eating, and used your crew, you arrive at the last couple of loops tired but functional, and you can grind out a finish. If you ran the smooth early loops too hard, this is where it falls apart, and a runnable course turns into a long walk. The 26 hour soft cutoff means you must start that eighth loop by 8:30 AM Sunday, so protect your buffer through the night instead of hoping to find it at the end.

Pacing strategy for a runnable loop 100

Umstead does not have the climbs or the heat that meter your effort for you, so the discipline is all on you. The whole game is starting slower than feels right and keeping enough in the tank for the night loops and the back half.

Run the early loops slower than feels right

On a smooth, gentle course your fresh-legs pace lies to you. The grades are runnable, so the temptation is to run them, but the smart move is to hold a relaxed effort and even hike the rolling hills early to save your legs. Use a grade-adjusted pace to set honest targets for the gentle climbs and the descents on the loop, so you are spending effort at a rate you can hold for 30 hours, not for the first marathon. The classic Umstead blow-up is banking time on loops 1 and 2 and paying for it triple on loops 7 and 8.

Build a finish prediction and work back to the cutoffs

Do not guess your Umstead finish off a road time. Even with gentle vert, 100 miles of cumulative climbing, fatigue, and the night all add up. A vert-aware finish prediction for this loop profile gives you a realistic window and a per-loop pace, so you can work backward into the 26 hour soft cutoff and the 30 hour limit and know exactly how much buffer you have when you roll through the start-finish each time. Looping makes this easy: you can check your real split against the plan eight times and adjust before it is too late.

⏵ Free tools to pace this course

Fueling strategy for 100 miles and a full night

A 100 miler is an eating contest with running attached, and Umstead is no exception. The good news is that constant crew and aid access make it one of the easier 100s to fuel well. The hard part is keeping the calories going for 24 to 30 hours, including through the night.

Carbs: steady, trained, and loop by loop

For an effort this long, aim for roughly 60 to 90 grams of carbohydrate per hour, leaning toward the high end only if your gut is trained for it. The smartest way to manage that on a looped course is to portion it: know what you are eating each loop and refill from your drop bag every time through the start-finish, so you never have to do mental math at mile 80. Practice your exact hourly carb number on long runs so 80-plus grams an hour feels routine, not like an experiment you are running for the first time on race day.

The night is where fueling quietly falls apart. Your appetite fades, real food gets harder to choke down, and that is exactly when your engine still needs the calories. Plan for it. Lean on liquid calories, gels, and easy-to-eat options for the overnight loops, and keep eating on a schedule even when you do not feel like it.

Sodium and fluid: dial it to your sweat and the day

Plan a sodium intake in the neighborhood of 500 to 700 milligrams per liter of fluid, more if you are a heavy or salty sweater. North Carolina spring can hand you anything from cool and damp to a warm, humid afternoon, so check the forecast and be ready to push sodium and fluid up if the day turns warm. Cramping, a sloshy stomach, and that hollow wrung-out feeling late in a 100 are usually fluid and sodium problems, not fitness problems.

The frequent aid (never more than about 3.8 miles between fluid stops) and the lap-by-lap crew access mean you do not have to carry a ton at once, which is a real advantage. Weigh yourself before and after a long run to find your true sweat rate, then build your per-hour plan around your own number rather than a generic chart.

⏵ Build your fueling plan

Get a carb, sodium, fluid, and caffeine plan per hour built for your weight, your goal time, and the Umstead duration 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 Umstead loop profile, and your projected splits. Summit Line reads your real training, builds a plan for the endurance and the night, and rehearses your fueling so race day is something you execute, not guess at.

Start free →Explore the demo

Umstead 100 FAQ

How hard is the Umstead 100 Mile Endurance Run?

Umstead is widely called one of the friendliest 100 milers in the country, and that is true on paper, but do not let that fool you into thinking it is easy. The footing is excellent and the climbing is gentle, only about 8,000 feet over the whole 100 miles on a wide powdered-granite bridle path, so the trail itself never beats you up. What makes it hard is everything else: eight laps of the same 12.5 mile loop, a full night out there, and a 30 hour clock that still asks you to keep moving. The difficulty here is mental and metabolic, not technical, which is exactly why it has been the classic place to make the jump from 50 to 100 miles since the 1990s.

How much elevation gain does the Umstead 100 have?

The course climbs roughly 8,000 feet over the full 100 miles, which works out to about 1,000 feet per 12.5 mile loop. By 100 miler standards that is genuinely modest, and there is nothing steep or technical, just well-spaced rolling hills on a smooth surface. The 50 mile option runs four of the same loops for about 4,000 feet of gain. Because none of the climbs are severe, you can run almost all of it, which sounds like a gift but is its own trap, since runnable terrain tempts you to go too hard early.

What is the course like at the Umstead 100?

It is a 12.5 mile loop in William B. Umstead State Park that you repeat eight times for the 100, four for the 50. The surface is packed powdered-granite bridle path, somewhere between 8 and 15 feet wide, with excellent footing the whole way, so you do not deal with roots, rocks, or technical trail. The loop rolls through wooded park with well-spaced hills and a couple of recognizable longer grades you will get to know intimately by the back half. You pass the start-finish at Camp Lapihio between every loop, which makes it about the easiest 100 miler in the country to crew.

What are the cutoff times for the Umstead 100?

The overall limit is 30 hours: the race starts at 6:30 AM Saturday and ends at 12:30 PM Sunday. There is a soft cutoff at 26 hours, 8:30 AM Sunday, at the start-finish, and to keep going you need to have started your eighth and final loop by then, which is the 87.5 mile point. Finish under 24 hours (by 6:30 AM Sunday) and you earn the one-day buckle. Those are the times that have held in recent years, but always confirm the current cutoffs in the race-day schedule before you toe the line.

How does the loop format and crewing work at Umstead?

The whole race is built around the 12.5 mile loop, and you come back through the start-finish at Camp Lapihio after every single one, so this is one of the easiest 100 milers anywhere to crew and to use drop bags. Your crew sees you eight times, which means you can carry less and reset every lap. Pacers are allowed starting at 6:30 PM, or at the beginning of your fifth lap if you get there earlier, so you can have company for the night miles. Aid is generous too: three fluid stops per loop mean you are never more than about 3.8 miles from water and support.

Is the Umstead 100 a good first 100 miler?

Yes, and that is basically what it was designed for. The smooth runnable surface, the gentle vert, the looped course with constant crew and aid access, and the generous 30 hour cutoff all stack the deck in favor of a first-timer who has done the work. The honest catch is that the same things that make it approachable also make it a mental test: running the same loop eight times, alone in the dark, is its own skill. If you build the endurance, rehearse your fueling, and prepare for the repetition and the night, Umstead gives most committed first-time hundred milers a real shot at the buckle.

This guide is independent and for planning only. The course details, date, cutoffs, aid stations, and pacer rules 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.