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⏵ Course guide · Washington ultra

Dark Divide 100 Miler Course Guide

The Dark Divide 100 is one of the meanest 100s in the Washington Cascades, run out of the Cispus Learning Center near Randle through the remote Dark Divide Roadless Area. You get over 26,000 feet of climbing, steep technical singletrack, long gaps between aid where you carry your own everything, and two nights under a 48 hour clock. It is a Hardrock qualifier, and it feels like one. I will walk you through the course, then give you pacing and fueling strategy built for exactly this kind of steep, remote, long day, plus free tools to dial in your own numbers.

⏵ At a glance

Dark Divide 100 quick facts

Date
100 Miler: Fri, Sep 4, 2026, 5:00 AM (event runs Sep 4 to 6)
Location
Cispus Learning Center, Randle, WA · Dark Divide Roadless Area, Gifford Pinchot
Distances
100M · 100K (point to point) · 50K · 15M fun run
Elevation gain
100M: over 26,000 ft of climb (similar descent) · 100K: roughly 16,500 ft
Start
100M 5:00 AM Fri · 100K 5:00 AM Sat · 50K 7:00 AM Sun · 15M 9:00 AM Sun
Cutoff
100M: 48 hours (final cutoff 5:00 AM Sunday), with intermediate cutoffs
Terrain
Over 75% singletrack, much of it quite technical, remote, minimal markings
Qualifier
Hardrock 100 qualifier

These facts come from the official Wonderland Running site and UltraSignup. The exact aid count, the full intermediate cutoff chart, the start day, and the route get tweaked year to year, so confirm the current date, cutoffs, and aid stations in the official race-day details before you commit.

The course: where Dark Divide is won and lost

The 100 miler starts and finishes at the Cispus Learning Center and runs big loops out into the Dark Divide Roadless Area, over 26,000 feet of climbing on more than 75 percent singletrack, much of it technical. This is not a course you race off a pace chart. It is a course you survive by climbing efficiently, descending under control, and never letting the long aid gaps catch you empty. Named aid points on the way home include Wright Meadow near mile 51.6, Summit Prairie near mile 71.4, and Juniper Ridge near mile 93.7.

The climbs: long, steep, and stacked

Over 26,000 feet of gain across 100 miles tells you the climbing here never really lets up. It does not come as a couple of famous passes you can mentally tick off. It comes as long, steep climbs on rough singletrack, one after another, with the meadows and ridgelines in between. The smart move is to hike the steep stuff early and often, keep your effort flat instead of your pace, and save your legs. Burn matches chasing a time on the first big loop and the Dark Divide will collect on that debt with interest later, in the dark.

Poles earn their weight on a course like this. If you can power hike efficiently on technical grade, you will move past people who are grinding it out on tired legs, and you will arrive at the climbs late in the race with something left in the tank.

The descents: technical and quad-wrecking

There is over 26,000 feet of descent to match the climb, and on this kind of rough, steep singletrack the downhills are not free speed. They are a skill and a tax. Rocky, rooty, off-camber footing means you cannot just let gravity take you, and if you bomb the early descents your quads will be cooked long before the finish. The runners who do well here descend light and controlled all day, then still have working legs at mile 80 when everyone else is reduced to a careful, painful shuffle.

Practice technical downhill running before you show up. Being able to keep your feet moving on rough ground, in the dark, on trashed legs, is honestly the single skill that separates finishers from DNFs on a course like this.

The remoteness and the long aid gaps

This is a self-reliant race, and it is the part people underestimate. The course runs through the Dark Divide Roadless Area with up to 16 miles between aid stations, minimal course markings, and crew that may be two hours or more away on rough forest service roads. You have to be able to take care of yourself out there: enough food and water to cross the longest gaps, a working light setup, layers for the cold, and the navigation focus to stay on a lightly marked course when you are tired.

Plan your carry around the longest leg, not the average one. Showing up to Wright Meadow, Summit Prairie, or Juniper Ridge already empty, or off course, is how good days fall apart here. Treat each aid station as a checkpoint you have to reach fully self-sufficient.

Two nights, sleep, and the late-race lows

With a 48 hour cutoff and terrain this slow, most runners are out here through two nights, and that changes everything. The temperature drops, the technical footing gets harder to read by headlamp, and somewhere in the small hours your brain starts negotiating. The mid-pack reality of this race is that you may sleep, or at least sit, and the people who plan for that, a quick reset at a drop bag instead of an aimless death spiral, come out the other side and keep moving.

Have a night plan. Know your drop bag spots, carry backup light and batteries, pack warm layers for the high meadows after dark, and decide in advance how you will handle the 3 AM lows before you are in them. The Dark Divide is won in those quiet, cold, dark hours as much as on any climb.

Pacing strategy for a steep, technical, two-night 100

With over 26,000 feet of climb and descent on technical ground, Dark Divide rewards patience, vert fitness, and durable quads far more than flat speed. Pace it by effort and grade, not by the watch, and respect the cutoffs from the first loop.

Pace the climbs by grade, not by your flat splits

Your road pace is meaningless on the Dark Divide climbs. What matters is grade-adjusted effort, so hold a steady output you can sustain up the grade and hike the steep pitches without feeling like you are giving anything away. The classic blowup here is running the early climbs too hard because fresh legs feel great, then paying for it on the technical descents and the second night. Use a grade-adjusted pace to turn your real fitness into honest climbing and descending targets, and you will not torch the first half of a race that is decided in the second.

Build a vert-aware finish prediction and work back into the cutoffs

Do not guess your Dark Divide finish off a road or even a runnable-trail 100 time. Over 26,000 feet of gain, the same in descent, the technical footing, the long aid carries, and two nights all add huge chunks of time. A vert-aware finish prediction that accounts for this course’s climbing gives you a realistic window, and then you can work backward into the 48 hour limit and the intermediate cutoffs, so you actually know how much buffer you have at each checkpoint instead of finding out the hard way.

Reality-check your goal before you commit

If you want to know how a recent race lines up against a steep, technical mountain 100 like this, run it through a race-equivalent calculator first. It is an easy way to sanity-check whether the time in your head is honest about the vert and the terrain, or whether it is a road dream that the Dark Divide is going to wake you up from somewhere around mile 60.

⏵ Free tools to pace this course

  • Grade-adjusted pace calculator to turn your flat fitness into honest effort targets for the long climbs and the technical descents.
  • Race-time calculator for a vert-aware finish prediction on this course’s 26,000-plus feet of climb, so you can plan against the cutoffs.
  • Race-equivalent calculator to turn a recent race result into a Dark Divide goal that is honest about the vert and the terrain.

Fueling strategy for the duration and the long gaps

A 100 miler that takes most people deep into a second day, with up to 16 miles between aid, makes carbohydrate, sodium, and how much you carry just as important as fitness. The runners who finish are the ones who keep eating when the terrain and the night kill their appetite.

Carbs: steady all day, and into the night

For an effort this long, aim for around 60 to 90 grams of carbohydrate per hour, leaning to the higher end only if your gut is trained for it. Use a glucose-plus-fructose blend so you can absorb more than a single sugar allows. The hard part on the Dark Divide is not the number, it is holding it for 24 to 48 hours over technical ground and through two nights, when your stomach is grumpy and food sounds awful. Practice your real hourly carb rate on long back-to-back training runs so it is automatic, and keep eating in the dark even when you do not feel like it. The low you are fighting at 4 AM is very often just a calorie deficit wearing a costume.

Sodium and fluid: carry for the longest leg

Bias your sodium toward the higher end, often around 500 to 700 milligrams per liter of fluid, and more if you are a heavy or salty sweater. Just as important on this course, carry enough food and fluid to cover the longest gaps between aid, up to 16 miles in the roadless country, instead of rationing to the next station and arriving wrung out. Weigh yourself before and after a long training run to find your real sweat rate, then build your carry and your electrolytes around your own number. Cramping and that hollow, empty late-race feeling out here are usually fluid and sodium problems, not fitness problems.

⏵ Build your fueling plan

Get a carb, sodium, fluid, and caffeine plan per hour built for your weight, your goal time, and the Dark Divide 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 Dark Divide course profile, and your projected splits. Summit Line reads your real training, builds a plan for the relentless vert and the technical descents, and rehearses your fueling for the long aid gaps and the two nights, so race day is something you execute, not guess at.

Start free →Explore the demo

Dark Divide 100 FAQ

How hard is the Dark Divide 100 Miler?

It is one of the harder 100s in the Washington Cascades, full stop. The 100 mile course packs over 26,000 feet of climbing with a similar amount of descent, and it is over 75 percent singletrack, much of it genuinely technical, through the remote Dark Divide Roadless Area. The footing is steep and rough, the markings are minimal, and you can travel up to 16 miles between aid stations out in the roadless country. You also get a 48 hour cutoff, which sounds generous until you are moving over that terrain through two nights. The race even calls itself a beast, and it earns it. Treat this as a mountain 100 where vert, technical skill, and self-sufficiency matter way more than flat speed.

How much climbing is in the Dark Divide 100?

The 100 miler has over 26,000 feet of total elevation gain, with roughly the same amount of descent, per the official race. That is a lot of vert for 100 miles, and it does not come in a few big mountain passes. It comes as long, steep climbs stacked one after another on technical singletrack, with the descents being just as rough on your legs as the climbs are on your lungs. The 100K, which runs point to point from Wright Meadow back to Cispus, carries roughly 16,500 feet of gain. So whichever distance you pick here, the climbing and the descending are the whole story.

What are the aid stations and crew access like at Dark Divide?

This is a remote, self-reliant race, so plan around long gaps. The course runs through the Dark Divide Roadless Area and you can go up to 16 miles between aid stations, which is a long way to be carrying your own food and water on technical ground. Named aid stations on the 100 include Wright Meadow around mile 51.6, Summit Prairie around mile 71.4, and Juniper Ridge around mile 93.7. Getting crew out to the South Loop aid can be two hours or more from Cispus on rough forest service roads, so this is not a race where your people pop over to every checkpoint. Pull the current aid station and cutoff chart from the official site and build your carry and your drop bags around it.

What are the Dark Divide 100 cutoff times?

The 100 miler has a 48 hour overall cutoff, with the final cutoff at 5:00 AM Sunday off the 5:00 AM Friday start. There are also intermediate cutoffs at points along the course, listed in the official aid stations and cutoffs document, and you should treat those as the real constraint, not the 48 hour number. On terrain this steep and technical your moving pace is slow, so the early and mid-race cutoffs can sneak up on you if you sit too long in aid or fall behind on the first big loop. Build your plan backward from the posted intermediate cutoffs with real buffer, and confirm them on the official site before race day.

When is the Dark Divide 100 and where does it start?

The Dark Divide Trail Races run September 4 to 6, 2026 (Friday to Sunday), out of the Cispus Learning Center near Randle, Washington, in the Gifford Pinchot National Forest. The 100 miler goes off first, at 5:00 AM Friday, then the 100K starts Saturday, and the 50K and the 15 mile fun run go on Sunday. The 100 mile and the shorter races start and finish at Cispus, while the 100K is point to point starting up at Wright Meadow. Dates and start times shift year to year, so always confirm the current schedule with the official race before you book travel.

Is Dark Divide a Hardrock qualifier?

Yes. The Dark Divide 100 Mile Endurance Run is a qualifier for the Hardrock 100, which fits its profile as a steep, high-vert, technical, remote mountain 100. A qualifying finish gets you into the Hardrock lottery, it does not get you a spot, since Hardrock entry is a separate low-odds lottery with its own rules. Qualifier lists get reviewed every year, so if you are running Dark Divide specifically to qualify, confirm its current Hardrock qualifier status, and the Hardrock entry requirements, on the official Hardrock and Dark Divide sites before you count on it.

This guide is independent and for planning and training only. The course details, dates, start times, cutoffs, aid stations, and qualifier status for the Dark Divide 100 come from public sources and can change year to year, so confirm the current specifics with the official race before you register, train, or travel. The fueling and pacing advice is general and not medical advice.