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⏵ Course guide · Oregon ultra

Waldo 100K Course Guide

Waldo is the classic high-Cascades 100K, run out of Willamette Pass near Oakridge, and it has earned its reputation: more than 11,000 feet of climbing on remote singletrack and PCT, big alpine views of Waldo Lake, and a 4 AM start that sends you into the dark. It is also a Western States qualifier, so a lot is riding on getting in under the cutoffs. I will walk you through the course first, then give you a pacing and fueling plan that fits the climbing and the long day. There are free calculators along the way to dial in your own numbers.

⏵ At a glance

Waldo 100K quick facts

Date
Saturday, August 1, 2026 (early August, third Saturday tradition has shifted; confirm the year)
Location
Willamette Pass Ski Area, Oregon Cascades, near Oakridge, about 70 miles southeast of Eugene
Distance
100K (course measures about 62.5 mi)
Elevation gain
More than 11,000 ft of gain (about 3,350 m), high point 7,818 ft atop Maiden Peak
Start
4:00 AM, in the dark, at Willamette Pass (about 5,120 ft)
Cutoffs
Charlton Lake 2:00 PM · Rd 4290 3:15 PM · The Twins (return) 5:30 PM · 18 hr overall (10:00 PM)
Qualifier
Western States Endurance Run qualifier (100K, 18 hr); always reconfirm on the current WSER list

These facts come from the official race site, the Western States qualifying list, and ITRA. Check the current date, cutoffs, and aid stations in the race-day details before you commit. Race logistics change year to year.

The course: where Waldo is won and lost

Waldo is a big lollipop out of Willamette Pass at about 5,120 feet, roughly 62.5 miles and over 11,000 feet of climbing, almost all of it on singletrack and a lot of it on the Pacific Crest Trail. The vert is front-loaded into a few huge climbs (Fuji early, then the Twins, then Maiden Peak late), and the second half is genuinely remote. From Rd 4290 at mile 37 to the finish, you do not cross a single road.

The first half: Gold Lake, Fuji, and settling in

You start in the dark and climb almost right away, dropping through Gold Lake before the long pull up Fuji Mountain, which is your first taste of the big alpine views over Waldo Lake. This early stretch feels great, which is exactly the trap. Everyone is fresh, the trail is runnable, and it is easy to spend energy you will desperately want at mile 50. Hike the steep pitches, run the runnable grades easy, and treat the whole first half as setup, not as the race.

After Fuji the course works through Mt Ray and toward the Twins, rolling forested PCT singletrack at altitude. Nothing here is technical in the gnarly sense, but the constant up and down adds up, and you are already over a mile high. Keep your effort honest and your eating on schedule while it is still easy to eat.

The back half: remote, climbing, and the late gates

The race really starts after Charlton Lake and Rd 4290, where the course turns remote and the intermediate cutoffs start biting. You pass back through the Twins a second time (a 1.5 mile hike up to the aid), then face the long climb toward Maiden Peak, the 7,818-foot high point, deep into the day when your legs are already cooked. The final stretch of aid stations sit at the top of steep hike-outs, which is brutal when you are hurting and the clock is ticking.

This is where Waldo is won or lost. If you paced the first half with discipline you can keep grinding the climbs and moving on the descents. If you spent too much early, the back half turns into a slow march against the cutoffs, and the 5:30 PM gate at the Twins ends a lot of days right there. Know your splits into those gates before you start.

Navigation, exposure, and the long day

Junctions are well marked, but the organizers warn that the remote sections carry minimal ribbons between turns, so stay awake out there and do not blindly follow the runner in front of you. You also start in real darkness, so a good headlamp (and a backup) is not optional. Aid stations run roughly 2.5 to 7.5 miles apart, with drop bags at Fuji, Mt Ray, Charlton, and Rd 4290, but a few gaps and the big climbs mean you should carry enough fluid and food to cover yourself, not just enough to reach the next table.

The weather can do anything. Cool 40s and 50s in the morning, 60s and 70s in the afternoon is typical, but it has ranged from the 20s to the 90s, and the high country can hold snow. Dress for a cold dark start and a potentially warm, exposed afternoon on the same day, and pack accordingly in your drop bags.

Pacing strategy for a long, climbing-heavy 100K

With over 11,000 feet of gain stacked into a few enormous climbs and a back half that closes on you with cutoffs, Waldo is about managing effort across a 12 to 18 hour day, not chasing a pace chart. Run the climbs by feel and protect your legs for the late miles.

Pace the climbs by grade, not by the watch

Your flat-ground pace is meaningless on the Fuji, Twins, and Maiden Peak climbs. What matters is grade-adjusted effort, so hold a steady output you can actually sustain uphill and hike the steep pitches without guilt. The classic Waldo mistake is running the early climbs hard because the legs feel fresh, then unraveling on the long back-half climbs in the afternoon. Use a grade-adjusted pace to turn your real fitness into honest climbing and descending targets, and you will arrive at Maiden Peak with something left.

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

Do not guess your Waldo finish off a road 100K or a flatter trail time. The 11,000-plus feet of climbing, the altitude, and the remote terrain all add real hours. A vert-aware finish prediction that accounts for this course profile gives you a realistic window, and just as important, it lets you work backward into the intermediate cutoffs (Charlton, Rd 4290, the Twins) so you know how much buffer you actually have at each gate instead of finding out the hard way.

⏵ Free tools to pace this course

Fueling strategy for a 12 to 18 hour mountain day

Most runners are out on Waldo for somewhere around 12 to 18 hours, climbing at altitude, through a cold start and a warm afternoon. That makes carbohydrate, sodium, and fluid every bit as important as fitness, and a fueling plan you have actually rehearsed.

Carbs: steady all day, and trained

For a day this long, aim for around 60 to 90 grams of carbohydrate per hour, and only push the high end if your gut is trained for it. The real enemy over 12-plus hours is your stomach quitting, not your legs, so keep intake steady and easy to get down from the very first hour instead of trying to claw calories back late. Practice your exact race-day carb rate on long back-to-back training days at effort, so 70 to 90 grams an hour feels routine and not like an experiment you are running mid-race.

Sodium, fluid, and the cold-start, warm-afternoon swing

Plan your sodium and fluid around the day you will actually get: a cold dark start where you may barely sweat, then a warm exposed afternoon up high where you will. As it warms, lean up on sodium (often 500 to 700 milligrams per liter of fluid, more if you are a heavy or salty sweater) and carry enough to cover the longer gaps and the big climbs, not just enough to reach the next aid. Use your drop bags at Fuji, Mt Ray, Charlton, and Rd 4290 to swap layers and reload exactly what you need. Weigh yourself before and after a long hot training run to find your real sweat rate, then build the plan around your own number.

⏵ Build your fueling plan

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

Start free →Explore the demo

Waldo 100K FAQ

How hard is the Waldo 100K?

Waldo is one of the harder 100Ks in the country, no question. You cover about 62.5 miles with more than 11,000 feet of climbing on remote alpine singletrack, much of it on the Pacific Crest Trail at real elevation, with a high point of 7,818 feet on Maiden Peak. The organizers list three major climbs over 2,000 feet each plus two more over 1,000, and the back half is genuinely remote: from the Rd 4290 aid station at mile 37 to the finish you never cross a road. It is not technical in the rock-scramble sense, but the length, the altitude, and the relentless climbing make it a true sufferfest.

How much climbing is in the Waldo 100K?

More than 11,000 feet of gain, with an equal amount of loss, over roughly 62.5 miles. The race is built around three major climbs of more than 2,000 feet each, plus two minor climbs over 1,000 feet, so the vert is stacked into big sustained efforts rather than spread out evenly. The high point is the optional Maiden Peak summit at 7,818 feet, late in the race, and the start at Willamette Pass already sits around 5,120 feet. Pace this by effort on the climbs, because your flat splits will lie to you all day.

What are the cutoff times for the Waldo 100K?

There is an overall 18-hour limit, so with the 4:00 AM start the course closes at 10:00 PM. Before that you have intermediate cutoffs you have to beat: roughly Charlton Lake (about mile 32) by 2:00 PM, Rd 4290 (about mile 37) by 3:15 PM, and the second pass through the Twins (about mile 45) by 5:30 PM. Those are the gates that end most days, so you cannot bank all your buffer for the finish. Always confirm the exact intermediate cutoffs in the current race-day instructions, since they get adjusted year to year.

Is the Waldo 100K a Western States qualifier?

Yes. Waldo 100K appears on the Western States Endurance Run qualifying-races list as a 100K with an 18-hour limit, which means a finish inside the cutoff earns you a qualifier for the WSER lottery. That is a big part of why it fills up and why people travel for it. Qualifying lists do change, so check the official WSER qualifying-races page for the current year before you count on it.

What is the terrain and weather like at Waldo?

The course is predominantly singletrack, with long stretches on the Pacific Crest Trail through high Cascades forest and around alpine lakes, with huge views of Waldo Lake from the high points like Fuji. It is runnable trail more than rock scrambling, but the second half is remote and lightly marked in places, so pay attention to junctions. Early August up there usually means cool mornings in the 40s and 50s and afternoons in the 60s and 70s, but it can swing from the 20s to the 90s, and snow at the higher elevations is not unheard of. Plan for a cold dark start and a potentially warm exposed afternoon in the same day.

How many aid stations does the Waldo 100K have?

There are nine aid stations, spaced roughly 2.5 to 7.5 miles apart, so you are rarely more than an hour or two from support if you are moving well. Drop bags are available at Fuji Mountain, Mt Ray, Charlton Lake, and Rd 4290. A few of the late stations sit at the top of steep hike-outs (the Twins, Maiden Peak), which matters when your legs are wrecked. Carry enough fluid and calories for the longest gaps and the climbs, especially across the remote back half where there are no road crossings.

This guide is independent and for planning only. The course details, dates, cutoffs, aid stations, and qualifier status come from public sources and can change year to year, so confirm the current specifics with the official race and the Western States qualifying list before you register or run. The fueling and pacing advice is general and not medical advice.