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⏵ Course guide · Washington ultra

Plain Endurance Runs (Plain 100) Course Guide

Plain is the most stripped-down hundred I know of. No aid stations, no course markings, no pacers, just you, two loops in the Wenatchee National Forest, and whatever you carried from Deep Creek. The 100 mile course climbs roughly 21,000 feet, your water comes from creeks, and for the first eight years almost nobody finished. I will walk you through the course and the navigation first, then give you a pacing and fueling plan built for a fully self-supported Cascade hundred, plus free tools to dial in your own numbers.

⏵ At a glance

Plain 100 quick facts

Date
Sat, September 19, 2026 (mid-September weekend)
Location
Wenatchee National Forest near Plain and Leavenworth, Cascades, WA
Distances
100 mile (two loops) and 100K (one loop)
Elevation gain
Roughly 21,000 ft on the 100 mile, three climbs near 5,000 ft each
Surface
About 85 mi of USFS trail plus about 20 mi of forest road
Start
5:00 AM
Cutoff
36 hours
Support / qualifier
No aid, no markings, no pacers (aid only at Deep Creek). Used as a Hardrock qualifier; not a WSER qualifier

These facts come from the official race site, UltraSignup, and the UltraRunning calendar. The date, exact course, checkpoints, and rules can change year to year, and wildfire has forced changes and cancellations before, so confirm the current details with the race before you commit.

The course: where Plain is won and lost

Plain is two loops out of Deep Creek in the Wenatchee National Forest, roughly 100 miles with about 21,000 feet of climbing on a mix of around 85 miles of Forest Service trail and about 20 miles of forest road. The 100K is a single loop. There is no flagging and no aid out there, so the course is as much a navigation and logistics problem as it is a running one. Where Plain gets won is in the boring stuff: knowing the route, managing your water, and keeping yourself fed and moving for a full day and night.

The navigation: an unmarked course you have to know

This is the thing that makes Plain different from almost every other hundred. There is no marked course and no flagging, so you are responsible for finding your own way the entire time. Finishers study the course directions, carry maps and a loaded GPS track, and know the junctions before they ever toe the line. People who have finished before still take wrong turns out here, usually deep in the night when they are tired and the trail forks in the dark.

Treat navigation as a trained skill, not a hope. Build the track on your watch, learn the key decision points, and pre-run sections if you can get out to the forest beforehand. A blown turn at Plain is not just bonus miles. It is the water and the food you budgeted for one leg getting spent on a leg you did not plan for, and that is how self-supported days unravel.

The climbs: three big efforts in the Cascades

The 100 mile route stacks its roughly 21,000 feet of climbing into a handful of long efforts, including three major climbs of close to 5,000 vertical feet each with the descents to match. This is honest Cascade mountain running, steep up and steep down, broken up by stretches of forest road where you can actually settle into a rhythm. Hike the steep grades efficiently and save your legs, because you are doing the whole loop again.

The road miles are a gift and a trap. They are runnable, so it is tempting to push them early when you feel good, but burning matches on loop one road sections is exactly how people show up to loop two with nothing left. Run the roads relaxed and let the climbs set your effort.

Deep Creek, the loops, and the second-lap reality

Deep Creek is the start, the finish, the 100K turnaround, and the one and only place you can resupply. At the end of loop one you can take all the aid and food you want there from your crew or anyone else, then you head back out to do it all again. That handoff is the most important logistics moment of your race, so plan it. Have your second-loop food, water capacity, lights, layers, and anything for your feet ready to grab so you are in and out, not sitting and stiffening up.

The second loop is where Plain earns its reputation. You are tired, you are doing terrain you already did once, and now a chunk of it is in the dark with the temperature dropping. The runners who finish are usually the ones who stayed patient and well fed on loop one and treated Deep Creek like a pit stop, not a rest stop.

Water from creeks and the long carries

You get nothing from anyone out here. Your water comes from streams and lakes, so you carry a way to treat or filter it and you plan your refills around the crossings you know are on the route. Running dry between sources is a real danger at Plain, especially on a warm, dusty September afternoon on an exposed climb, so err toward carrying more than feels necessary and top off whenever you pass reliable water.

This is where knowing the course pays off twice. If you know where the next reliable creek is, you know how much to carry and you are not rationing on a guess. Get the water math wrong and the day gets dangerous fast, no matter how fit you are.

Pacing strategy for a self-supported two-loop hundred

Plain rewards patience and good logistics far more than raw speed. With about 21,000 feet of climbing, no aid to lean on, and a full night out there, you pace this by effort and you build margin against the 36 hour clock from the first climb.

Pace the climbs by grade, not by the watch

Your flat-ground pace tells you almost nothing on the big Plain climbs. What matters is grade-adjusted effort, so hold a steady, conversational output you can sustain up the grade and hike the steep pitches without feeling bad about it. The classic blowup is pushing the runnable road grades and the early climbs on loop one because you feel fresh, then falling apart on the second loop. Use a grade-adjusted pace to turn your real fitness into honest climbing and road targets, and you will get back to Deep Creek with something left for lap two.

Build a vert-aware finish prediction against the 36 hour cutoff

Do not guess your Plain finish off a road or even a marked-trail hundred. The 21,000 feet of climbing, the self-supported carries, the water stops, and the time you lose to navigation all add up. A vert-aware finish prediction that accounts for this much climbing gives you a realistic window, and then you can work backward from the 36 hour cutoff to know how much buffer you actually have at Deep Creek and how hard you can afford to push the second loop.

Plan the night and the lows

You are going to be out here in the dark, probably for the back half of loop two, and that is when navigation gets hard and the temperature drops. Plan for it. Know which sections you will hit at night, carry enough light and battery, and expect the low patches that come with being tired, cold, and alone on an unmarked course. The runners who finish Plain are usually not the fastest. They are the ones who kept eating, kept their head together through the night, and just kept moving toward the next junction.

⏵ Free tools to pace this course

Fueling strategy when you carry everything yourself

Plain flips the usual fueling problem. There is no aid table to graze, so every calorie and every milligram of sodium has to come out of what you carried from Deep Creek. That makes a rehearsed, packable plan as important as your fitness.

Carbs: steady, trained, and packed for the whole loop

For an effort this long, aim for somewhere around 60 to 90 grams of carbohydrate per hour, and only push the higher end if your gut is trained for it. The catch at Plain is that you have to physically carry all of it for an entire loop, so you cannot wing it on aid-station snacks. Do the math: hours on each loop times your hourly carb target, then pack that plus a margin, and split your resupply at Deep Creek for the second lap. Rehearse your exact race-day carb rate on long training runs so 70 to 90 grams an hour feels normal, not like an experiment you are running for the first time out in the forest.

Sodium and fluid: ration to the next creek

Your fluid comes from streams and lakes, so carry a filter or treatment and 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. The real skill here is matching your carry to the gaps between reliable water. Know where the next creek is, carry enough to get there with a buffer, and top off every time you pass good water on a warm afternoon. Weigh yourself before and after a hot long run to find your real sweat rate, then build the plan around your own number instead of a guess.

⏵ Build your fueling plan

Get a carb, sodium, fluid, and caffeine plan per hour built for your weight, your goal time, and a long self-supported day with the free ultra fueling calculator, then total it up per loop so you know exactly what to carry from Deep Creek. 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 Plain course profile, and your projected splits. Summit Line reads your real training, builds a plan for the big Cascade climbs and the back-to-back loops, and rehearses your fueling so a fully self-supported day is something you execute, not guess at.

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Plain 100 FAQ

How hard is the Plain Endurance Runs (Plain 100)?

Plain is one of the hardest hundreds in the country, and the difficulty is not really about the terrain numbers. It is fully self-supported with no aid stations, no course markings, and no pacers, so you carry everything you start with, you get your water from creeks and lakes, and you navigate the whole thing yourself. The 100 mile course is two loops in the Wenatchee National Forest with roughly 21,000 feet of climbing, including three big climbs near 5,000 feet each, and the only place you can resupply is at Deep Creek between the loops. For the first eight years almost nobody finished, and even now only about half the starters make it, so a finish here means something. The 36 hour clock is generous on paper, but getting lost, running out of water, or running out of food is what actually ends most days.

How much climbing is in the Plain 100?

The 100 mile course has roughly 21,000 feet of total climbing across the two loops, and it is stacked into a few long efforts rather than spread out evenly. There are three major climbs of close to 5,000 vertical feet each, with the matching descents to go with them, so this is real Cascade mountain running and not rolling trail. The surface is mixed, about 85 miles of Forest Service trail plus about 20 miles of forest road, which means long runnable road grades as well as the steep stuff. The 100K is one loop with about half the distance and a big share of that vert.

Are there aid stations or pacers at Plain 100?

No. This is the whole point of Plain. There are no aid stations on the course, no course markings, and no pacers or dogs allowed, and you may not stash food or water or use drop bags out on the trail. The single exception is Deep Creek, the start, finish, and 100K turnaround, where you can take all the aid and resupply you want from anyone before you head out on the second loop. There are search and rescue checkpoints where you stop and give your bib number and a password so the race can track you, but they are safety checkpoints, not aid. Your water comes from streams and lakes, so you treat or filter and you plan your refills around known crossings.

What are the cutoff times for the Plain 100?

The overall limit is 36 hours from the 5:00 AM Saturday start. That sounds roomy for 100 miles, and for a marked, aided race it would be, but Plain is neither. Time bleeds away here from navigation mistakes, water stops, and the simple cost of carrying everything yourself over 21,000 feet of climbing. Confirm the current cutoff and any checkpoint timing in the race rules before you start, since the details can change year to year.

How do you navigate the Plain 100 with no course markings?

You learn the route. There is no flagging and no marked course, so finishers study the course directions, carry maps and a GPS track, and know the key junctions cold before race day. People who have finished before still get lost out there, usually late, tired, and in the dark, so good navigation is a real skill you train, not an afterthought. Pre-running sections if you can get to the Wenatchee National Forest, building the track on your watch, and rehearsing the decision points are some of the highest-return prep for this race. A wrong turn does not just cost the bonus miles, it costs the water and food you budgeted for the leg you were supposed to be on.

What is the terrain and weather like at Plain?

The course runs on a mix of about 85 miles of Forest Service trail and about 20 miles of forest road through the Wenatchee National Forest in the Cascades, with three big climbs and descents near 5,000 feet. Mid-September on the east side of the Cascades can swing a lot in a day. Warm, dry, dusty afternoons and cold nights up high, and an early autumn cold snap or rain is always possible. You are out for a full day and night, so you plan for heat in the sun and real cold after dark, and you carry layers and light because there is no aid to bail you out.

This guide is independent and for planning only. The course details, date, cutoff, route, and rules come from public sources and can change year to year, and wildfire has forced reroutes and cancellations in the past, so confirm the current specifics with the official race before you register or run. Plain is fully self-supported and navigation is your responsibility. The fueling and pacing advice is general and not medical advice.