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⏵ Course guide · Virginia ultra

Bull Run Run 50 Miler Course Guide

The Bull Run Run 50 Miler is a VHTRC classic, one of the oldest 50-milers in the country and a favorite first 50 for a reason. It runs the length of the Bull Run Occoquan Trail out of Hemlock Overlook, rolling single-track along the river with no big mountains but a whole lot of short ups and downs, the famous bluebells early, and the infamous Do Loop late. I will walk you through the course first, then give you a pacing and fueling plan that fits the rollers and the distance. There are free calculators along the way to dial in your own numbers.

⏵ At a glance

Bull Run Run 50 quick facts

Date
Early April, first Saturday (2026 ran Sat, April 4)
Location
Hemlock Overlook Regional Park, Clifton, VA (Bull Run Occoquan Trail)
Distance
50 miles (about 50.2 mi)
Elevation gain
About 5,280 ft cumulative; constant short rollers, no single hill over about 200 ft
Start
6:30 AM EDT (no early starts)
Cutoff
13 hr overall (7:30 PM); soft cut at Hemlock (mi 17.6) 11:30 AM, plus hard cuts at Do Loop, Fountainhead, and Bull Run Marina late
Aid stations
12 along the course, fully stocked; you run through, never turn around at one
Qualifier
No Western States, UTMB, or Hardrock qualifier status listed by the race

These facts come from the official VHTRC race site and RunSignup. The race is traditionally the first Saturday of April, so confirm the exact upcoming date, cutoffs, and aid stations in the current race-day details before you commit. Race logistics change year to year.

The course: where Bull Run Run is won and lost

The course is a double out-and-back on the Bull Run Occoquan Trail, about 50.2 miles and roughly 5,280 feet of cumulative climbing, with a loop bolted onto each end. From Hemlock Overlook you head north for the Bluebell Loop and back, then south through the river miles to the Do Loop and back. Almost all of it is single-track dirt, and you run straight through every aid station because you never actually turn around at one.

The Bluebell Loop and the early miles: bank patience, not time

The first chunk of the day heads north to the Bluebell Loop, run counter-clockwise, through some of the biggest bluebell stands on the East Coast. If the early-April bloom lines up it is genuinely beautiful, and it is easy to get pulled along feeling fresh. That is the trap. This is the most runnable, gentlest part of the whole course, so the move is to hold back, keep your effort easy, and let people go who are spending matches they will want back at mile 40.

These early miles are also where you set your fueling rhythm and your footing habits for the day. The trail is rolling but smooth here, so use it to settle in, eat on schedule, and get used to the constant small ups and downs instead of charging them.

The rolling river miles: the relentless middle

Once you are back through Hemlock and heading south, the race becomes a long string of short rollers along Bull Run and the Occoquan. None of these hills is big, most are around 150 feet, but they never stop, and that is the real character of this course. The total vert adds up to about a mile, almost all of it in these little climbs and drops, so your legs take a steady beating even though nothing looks hard on the elevation chart.

There are several stream crossings through here, with bridges that can be slick and unstable, and depending on conditions your feet are probably getting wet. Roots, mud, and the odd fallen tree keep you honest. The smart play is to power-hike the short steep ups, run the downs and flats easy, and stop fighting the terrain. Fighting every little hill is how you arrive at the Do Loop with nothing left.

The Do Loop: the crux nobody forgets

Way down at the southern end, somewhere around mile 33, you hit the infamous Do Loop, a roughly 3-mile loop that comes exactly when your legs are already cooked. This is where the race is decided. It is not the hardest terrain on paper, but it lands at the worst possible moment, and the hard time cutoffs cluster right here, so this is where tired runners either grind it out or come undone.

Get through the Do Loop and you head back to Fountainhead and retrace the river miles to the finish (you do not repeat the White Loop on the way home). Those return miles feel longer than they are because you already know every roller. If you paced the first 30 miles with the Do Loop in mind, this is where smart pacing pays you back.

Pacing strategy for a rolling, cutoff-gated 50

With about 5,280 feet of gain spread across dozens of little rollers and a generous but real set of cutoffs, Bull Run Run is about even effort and steady forward motion, not chasing a pace chart. The people who blow up here almost always spent too much on the smooth early miles.

Run the rollers by effort, hike the short steeps

Your flat-road pace will lie to you on this course because the constant ups and downs scramble your splits. Run by effort instead: keep a steady, conversational output, run the downs and flats easy, and power-hike the short steep pitches rather than running them just because they are short. A grade-adjusted pace turns your real fitness into honest targets for the rollers, so you are not unknowingly redlining a hundred little hills and torching your legs before the Do Loop.

Build a finish prediction and back it into the cutoffs

Do not guess your Bull Run Run finish off a road 50-miler number. The rolling vert, the muddy footing, the stream crossings, and the late Do Loop all add real time. A vert-aware finish prediction gives you a realistic window, and then you can back it into the actual cutoffs (the 11:30 AM soft cut at Hemlock, the mid-afternoon hard cuts around the Do Loop and Fountainhead, and the 6:00 PM at Bull Run Marina) so you always know how much buffer you have at each checkpoint instead of finding out the hard way.

⏵ Free tools to pace this course

Fueling strategy for a long day on your feet

Most runners are out on the Bull Run Run 50 for somewhere around 9 to 13 hours, and the aid stations are frequent and well stocked. That is a long time to keep eating, so carbohydrate, sodium, and a steady stomach matter as much as your legs do.

Carbs: steady all day, and trained

For a 9 to 13 hour effort, aim for around 60 to 90 grams of carbohydrate per hour, and only push the higher end if your gut is trained for it. The danger on a long, cool day like this is not the heat, it is just forgetting to eat as the hours stack up and your appetite fades. Use the frequent aid stations, but do not rely on grazing alone; carry what you need and eat on a clock. Practice your exact race-day carb rate on long runs so taking in real calories deep into the day feels normal, not forced.

Sodium, fluid, and wet feet

Early April here is usually cool, so your fluid and sodium needs are more moderate than a summer ultra, but they still add up over 50 miles. A common starting point is roughly 300 to 600 milligrams of sodium per liter of fluid, more if you are a heavy or salty sweater or if it turns into one of those surprise warm spring days. Weigh yourself before and after a long run to find your real sweat rate and build from your own number. And plan for wet feet: with multiple stream crossings and likely mud, trained feet, good socks, and maybe a dry-sock swap in a drop bag will save your race from blisters.

⏵ Build your fueling plan

Get a carb, sodium, fluid, and caffeine plan per hour built for your weight, your goal time, and a long 50-mile 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 Bull Run Run course profile, and your projected splits. Summit Line reads your real training, builds a plan for the relentless rollers and the distance, and rehearses your fueling so race day is something you execute, not guess at.

Start free →Explore the demo

Bull Run Run 50 FAQ

How hard is the Bull Run Run 50 Miler?

Bull Run Run is considered one of the more accessible 50-milers in the country, but accessible does not mean easy. The course runs about 50.2 miles along the Bull Run Occoquan Trail with roughly 5,280 feet of cumulative climbing, and none of it comes in one big mountain. Instead you get constant short rollers, river-trail footing with roots and mud, and several stream crossings, so the difficulty is the relentless little ups and downs plus the distance. The 13-hour limit is generous, which is a big part of why it has a reputation as a great first 50.

How much climbing is in the Bull Run Run 50?

The course has about 5,280 feet of cumulative gain across the 50.2 miles, which famously adds up to about one vertical mile. The catch is that there is no single big climb. Almost all of it comes from dozens of short rolling hills along the river, most around 150 feet and none much over 200 feet. That makes it runnable on paper, but the steady up-down-up-down grinds on your legs over 50 miles in a way a couple of big climbs would not.

What are the Bluebell Loop and the Do Loop?

Bull Run Run is a double out-and-back with a loop at each end. Early on you run the Bluebell Loop at the northern end, which winds through some of the largest bluebell stands on the East Coast and is gorgeous if the early-April bloom lines up. Late in the race, down at the southern end, you hit the infamous Do Loop, a roughly 3-mile loop that comes when your legs are already cooked around mile 33. The Do Loop is the mental and physical crux of the day, so save something for it.

What are the cutoff times for the Bull Run Run 50?

The overall limit is 13 hours, with a 6:30 AM start and a 7:30 PM finish cutoff. There is a soft early cutoff at the Hemlock aid station around mile 17.6 at 11:30 AM, then a series of hard cutoffs late in the race: roughly Do Loop-Out near mile 35.5 at 3:45 PM, Fountainhead near mile 37.9 at 4:15 PM, and Bull Run Marina near mile 44.8 at 6:00 PM. They are set generously so that if you keep moving you have time to make the 13-hour limit, but confirm the exact times in the current race-day details before you start.

What is the terrain and weather like at Bull Run Run?

The course is almost entirely single-track dirt trail along Bull Run and the Occoquan River, with only a few short rocky sections. Expect roots, mud, fallen trees, and several stream crossings where bridges can be slick and your feet are probably getting wet. Early April in Northern Virginia is usually pleasant, but it is a coin flip: some years it is one of the first warm, humid days of spring, and other years it is chilly with a remote chance of snow. Brutal heat is unlikely that early, but plan for mud and wet feet no matter what.

Is the Bull Run Run 50 a good first 50-miler?

Yes, it is one of the most recommended first 50-milers anywhere, and that reputation is earned. The course has no huge climbs or technical mountain terrain, the 13-hour cutoff gives most prepared runners room to finish, the aid stations are frequent and well stocked, and the entry fee is reasonable. That said, the day can still bite: in 2026 only about 46 percent of starters finished on a tough day. Train the rolling hills, get comfortable on muddy single-track and wet feet, rehearse your fueling, and respect the late-race Do Loop, and it makes a great goal race for a first 50.

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.