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Western States 100 Course Guide

The Western States 100 is the oldest and most coveted 100 miler in the sport, a point-to-point run from Olympic Valley to Auburn across the Sierra Nevada and Gold Country. You get a high-altitude start, snow up high in big years, brutal canyon heat in the middle, a huge net descent that shreds quads, and a fast 30 hour clock. I will walk you through the course, then give you pacing and fueling strategy built for exactly those conditions, plus free tools to dial in your own numbers.

⏵ Quick facts

Western States at a glance

Date
Sat, June 26, 2027
Location
Sierra Nevada / Gold Country, CA
Start / Finish
Olympic Valley to Auburn (Placer High School track)
Distance
About 100.2 miles, point to point
Elevation
Roughly 18,000 ft of climb, about 23,000 ft of descent
High point
Emigrant Pass, about 8,750 ft (near mile 4.5)
Time limit
30 hours (5:00 AM Sat to 10:59 AM Sun)
Qualifier / entry
Lottery entry, UTMB World Series qualifier

Note: snow levels, river flow at the Rucky Chucky crossing, and even short reroutes change year to year, and entry is a low-odds lottery. So before you plan your race, confirm the date, exact route, cutoffs, and entry rules on the official WSER site.

The course

Western States follows the middle part of the historic Western States Trail, point to point from Olympic Valley near Lake Tahoe to the finish on the track at Placer High School in Auburn. It is about 100.2 miles of high-country singletrack, old-growth forest, deep river canyons, and Gold Country trail. You climb roughly 18,000 feet but you descend about 23,000 feet, so the whole thing tilts downhill. The high point is Emigrant Pass at roughly 8,750 feet, and you hit it in the first few miles.

The escarpment and the high country

The race starts at 5:00 AM in Olympic Valley at about 6,200 feet, and the first thing it does is climb hard. Roughly 2,550 vertical feet in the first 4.5 miles up to Emigrant Pass at around 8,750 feet, the high point of the day. You gain all that altitude before the sun is even up, on fresh legs and a body that is not warmed up yet. It is a sneaky opening. Easy to attack, and easy to regret.

From the pass you run through high-altitude singletrack and old-growth forest that, in heavy snow years, can still be partly under snow well into June. Pace this part by effort and by breathing, not by your sea-level numbers. The altitude makes every grade feel harder than it is, and the day is way too long to be burning matches up high.

The canyons and the heat

After the high country you head down toward the part that defines this race, the canyons. Long steep plunges drop into drainages like Deadwood, then you get short savage climbs back out, the worst being the roughly 1,500 foot wall up to Devils Thumb around mile 48 and the climb to Michigan Bluff near mile 56. This is the heart of the race.

It is also where the heat lives. You spend a cold, maybe snowy morning up high, and then the canyons in the afternoon routinely push past 100 degrees and have hit around 110. The mix of relentless descents, sharp climbs, and oven heat between roughly Robinson Flat and the river is where most Western States races are won or lost. Stay on top of your core temperature with ice and water every chance you get.

Foresthill, the river, and the run to Auburn

Foresthill, around mile 62, is the biggest and easiest to reach crew and pacer point, and most runners grab a pacer here for the final third. From town you drop back into the quiet on a long, rolling 16 mile descent toward the bottom of the American River canyon and the famous ford at Rucky Chucky near mile 78. In normal years you wade across or get guided over on a cable, and in high-water years you cross by raft.

The last stretch climbs out the far side toward Auburn, crosses the historic No Hands Bridge, and finishes with a final climb to Robie Point before the track at Placer High School. The closing miles are runnable. That rewards anyone who saved their legs, and it punishes anyone who did not.

Aid stations and cutoffs

You have roughly 22 aid stations along the way with water, electrolyte fluids, food, ice, and medical aid, and drop bags are allowed at the designated checkpoints. The major crew points are Robinson Flat near mile 30, Michigan Bluff near mile 56, Foresthill near mile 62, and the river area near mile 78.

The overall limit is 30 hours, a 5:00 AM Saturday start to a 10:59:59 AM Sunday finish, which is roughly an 18 minute per mile average across everything. The intermediate cutoffs at the aid stations are strictly enforced, and they go off the time you LEAVE, not the time you arrive. Pull up the official WSER cutoff chart for the current edition and build your plan backward from those times with a buffer.

Pacing strategy for Western States

A net-downhill, hot, high-start 100 miler rewards quad durability and heat discipline way more than raw climbing fitness. Pace this course by effort and by grade, and treat the descents as the real test.

Protect your quads from the first descent

The course drops about 23,000 feet, so downhill running is the crux of Western States, not the climbing. The runners who finish strong are the ones who run the early and middle descents controlled and light instead of letting gravity hammer their legs. Trash your quads up high and in the canyons, and that long runnable final third turns into a death march.

Use our free grade-adjusted pace calculator to turn your flat fitness into honest effort targets for the steep descents and short canyon climbs. Then you actually know whether you are running the downhills sustainably or cashing in legs you are going to want at mile 80.

Pace the heat, not just the miles

Run your race in two halves. Get to the canyons with fresh legs and a cool core, then survive the hot middle without blowing up. In the worst heat, slowing down on purpose to keep your core temperature in check is actually faster over 100 miles than pushing and cooking yourself. Bank time early only if you can do it without overheating, which for most runners means barely at all.

To set a finish goal that is honest about the descent and the heat, use our vert-aware race time calculator. Then check it against the strict 30 hour cutoff so your plan has real margin in it, not just hope.

Respect the altitude start and the night

That early climb to Emigrant Pass near 8,750 feet is going to feel harder than the same grade at home, especially if you live at sea level, so pace the first few miles by breathing and effort. Then plan for the night. After the river your pace can come back as it cools, but only if you stayed disciplined through the hot canyons and kept eating the whole way.

If you want to know how a recent race lines up against a 100 mile mountain effort like this, our race equivalent calculator helps you reality-check your goal time before you commit to it.

Fueling strategy for Western States

The canyon heat makes fueling and hydration matter as much as fitness at Western States. Heat is the thing that wrecks most well-trained runners here, so build your plan around it from the start.

Carbs: ramp to the high end, on a trained gut

For an effort this long, target roughly 60 to 90 grams of carbohydrate per hour, leaning toward the high end once your gut is trained to handle it. Use a glucose-plus-fructose blend so you can absorb more than a single sugar lets you, and rehearse your exact hourly carb number on long training runs so 80 to 90 g/h feels normal, not like an experiment, on race day.

The heat makes this harder, because a hot, sloshing stomach takes less. Practice fueling in race-like heat, and keep eating through the hot canyon hours when your appetite is gone but your engine still needs the fuel.

Sodium and fluid: built for the canyons

In the canyons your sweat and sodium losses can be huge, so bias your sodium toward 500 to 700 mg per liter of fluid, often higher if you are a salty sweater, and carry enough to cover the long, hot, dry stretches between aid stations. Cramping, a sloshy stomach, and that hollow wrung-out late-race feeling are usually fluid and sodium problems, not fitness problems.

Get a plan of your own with our free ultra fueling calculator. Put in your weight, your goal time, and the expected canyon heat, and it gives you a carb, sodium, fluid, and caffeine number per hour built for the Western States duration and conditions. Then go test it in the heat.

Train for the conditions

Western States asks for a lot at once: heat, altitude, downhill durability, and 100 mile endurance. These guides go deep on the parts that decide your day.

⏵ Free calculators for this race

Run your Western States numbers with our free, no-signup tools, then let Summit Line tie them all together with your real fitness and this exact course.

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⏵ Train for Western States

Get a race-day plan built around YOUR fitness, this exact course profile, and your projected splits. Summit Line reads your actual training, builds a fueling and pacing plan around the Western States descent and canyon heat, and tracks how your gut and legs handle the load, so race day is rehearsed instead of guessed.

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Western States 100 FAQ

How hard is the Western States 100 (WSER)?

If you only look at the elevation profile you will get the wrong idea about this race. It has roughly 18,000 feet of climbing across about 100.2 miles, which is not much for a mountain 100, but it loses around 23,000 feet. That net descent is what wrecks people, and it goes after quads that are not ready for it. You start high in Olympic Valley and climb to Emigrant Pass near 8,750 feet in the first few miles, the high country can hold snow in big years, and then it drops you into the canyons where the afternoon can run past 100 degrees. Then add a fast 30 hour clock, the river ford at Rucky Chucky, and a full night out there. So yes, it is hard, and getting in is hard too. Entry is a lottery with very long odds, so just making the start line is something.

How much climbing and descending is in the Western States 100?

The course climbs roughly 18,000 feet and descends about 23,000 feet across the full 100.2 miles, so you finish several thousand feet lower than you started. The biggest climb comes right away, about 2,550 vertical feet in the first 4.5 miles up to Emigrant Pass at roughly 8,750 feet, which is the high point of the day. After that you trend down toward Auburn, but you do it through the canyons, and they are not gentle. Steep plunging descents, then short savage climbs back out, the most famous being the drop into the Deadwood drainage and the roughly 1,500 foot wall up to Devils Thumb around mile 48. The climbs are not what get you here. The descents are.

How should I fuel for the Western States 100?

You are fueling a long day in serious heat, so plan for both. Most runners target 60 to 90 grams of carbohydrate per hour, leaning toward the high end once the gut is trained, and a sodium concentration around 500 to 700 mg per liter of fluid, often higher, because the canyon heat pulls a lot of sweat and sodium out of you. Your fluid needs jump in the hot middle of the race, so carry enough to cover the long dry canyon stretches, and use the aid stations to cool yourself down with ice and water. Practice your hourly carb and sodium numbers in the heat before race day, not on race day. Our free ultra fueling calculator takes your weight, goal time, and the expected heat and gives you a carb, sodium, and fluid plan per hour.

What are the Western States 100 cutoffs?

The overall limit is 30 hours, from a 5:00 AM Saturday start to a 10:59:59 AM Sunday finish, which works out to roughly an 18 minute per mile average across the whole course. There are also intermediate cutoffs at the aid stations along the way, they are strictly enforced, and here is the part people miss: they are the times you have to LEAVE each aid station, not arrive. The official WSER cutoff chart lists each one for the current edition. The clock is genuinely tight if you are mid-pack, so do not plan on making it up late. Keep margin against the early and mid-race cutoffs so the canyons and the night do not put you behind.

How hot does Western States get, and how do I prepare?

Very hot. You start cold, sometimes in snow up high, and then the race drops into the canyons where the afternoon regularly climbs past 100 degrees and has hit around 110. The stretch between roughly Robinson Flat and the river is where most of the damage gets done. The best thing you can do about it is heat acclimation in the two to three weeks before the race, with sauna or hot training sessions, and honestly that is one of the highest-return things on this whole list. On race day, stay on top of your core temperature. Ice in a bandana and sleeves, water over the head, and a drink-and-electrolyte plan you actually stick to. Treat the hot canyon hours as survival, and once it cools off you can run again.

How do you get into Western States, and is it a qualifier?

Western States is one of the hardest races in the world to even get into. Most runners get in through an annual lottery after finishing a qualifying race, the odds are low, and plenty of people wait years for their number to come up. There are also a small number of spots through the Golden Ticket races and a few other channels. Western States itself is a UTMB World Series qualifier, and a finish here carries a lot of weight in the sport. The qualifying standards, lottery rules, and entry process get updated every year, so always confirm the current ones on the official WSER website.

This guide is for planning and training, and it reflects publicly available information about the Western States 100. Race details, including the date, course, snow and river conditions, aid stations, cutoffs, and entry and lottery rules, can change year to year. So always confirm the current specifics on the official WSER race website before you train or travel.