The Western States Endurance Run is conducted along the Western States Trail starting at Olympic Valley, California, and ending in Auburn, California. The Run begins at 5:00 a.m. on Saturday of the last full weekend in June at the west end of Olympic Valley. Runners must reach the finish line no later than 10:59:59 a.m. on the following day in order to be eligible for an award. All entrants must strictly adhere to the Performance Rules, Rules for Pacers, Rules for Crews and to the pre-event briefing by Run Management to avoid disqualification and to remain eligible for an award.

The Western States Endurance Run follows the middle portion of the famous Western States Trail, a nationally dedicated recreational trail that stretches from Salt Lake City, Utah, to Sacramento, California. One of the most arduous organized running events in the U.S., the Western States 100 is truly the “Ultimate Challenge” for the long distance runner. Entry in this event should not be taken lightly!

Beginning in Olympic Valley, site of the 1960 Winter Olympic Games, the trail ascends from the valley floor (elevation 6,200 feet) to Emigrant Pass (elevation 8,750 feet), a climb of 2,550 vertical feet in the first 4½ miles. From the pass, following the original trails used by the gold and silver miners of the 1850’s, runners travel west, climbing another 15,540 feet and descending 22,970 feet before reaching Auburn, a small town in the heart of California’s historic gold country. Most of the trail passes through remote and rugged territory. People who are unfamiliar with the area should use caution when planning training runs, especially in the high country. Before leaving, let someone know where you will be running and when you will return. REMEMBER THAT MUCH OF THIS TERRITORY IS ACCESSIBLE ONLY BY FOOT, HORSE OR HELICOPTER.

Due to the remoteness and inaccessibility of the trail, the Western States Endurance Run differs substantially from other organized runs. Adequate mental and physical preparation are of utmost importance to each runner, for the high mountains and deep canyons, although beautiful, are relentless in their challenge and unforgiving to the ill-prepared.

1. Course Route: The Run will follow the same basic course used since 1986 unless snow conditions force a route change.
2. Familiarity: Knowledge of the trail offers both physical and mental advantages during the Run. Participants should make a reasonable effort to run as much of the trail as possible before Run Day. Particular attention should be given to those sections that you expect to run in the dark, when your mental and physical energy may be lagging.
3. After Dark: AS ALMOST A HALF OF THE TRAIL MAY BE TRAVELED AT NIGHT, EACH RUNNER SHOULD CARRY TWO LED FLASHLIGHTS. If your lights fail, wait for another runner with a light. Do not try to find your way in the dark. If you are the last runner, wait for the Search and Rescue sweep teams. Plan to pick up a flashlight in Foresthill, regardless of what time you reach that point. If you are a 28 to 30-hour runner, plan to pick up a flashlight in Michigan Bluff.
4. Weather: Since temperatures during the Run can range from 20 degrees to above 110 degrees Fahrenheit, participants should be fully prepared for both extremes. Weather conditions are unpredictable and can change rapidly.
5. River Crossing: At 78 miles, runners must ford the American River near the Rucky Chucky crossing. The ford is dangerous and SHOULD NOT BE ATTEMPTED ON TRAINING RUNS. On Run Day, a guide rope will be stretched across the river, with personnel available for assistance. River rafts are used in high-water years.
6. Wilderness: The remoteness of the trail can lead to disaster for anyone not experienced in the “backwoods.” For your own well-being and survival, we recommend that you do not attempt a training run alone without letting someone know exactly where you are going and what time you will return. Trail markings will not be completed until a few days prior to the Run. We strongly advise people who are unfamiliar with the area to buddy up with a “native guide.” Carry ample fluids, a water filtration pump and food supplies. There are dry stretches of over 8 miles during the Run and of 16 or more miles during training runs.
7. Trail Markings: Trail markings will consist of pink surveyor’s tape tied to branches, “W.S. TRAIL” signs nailed to trees, and arrows and signs. (“Pioneer Express Trail” markers are located along portions of the trail. Do not refer to these as Run markers.) In addition, reflectors will be placed along the last 38 miles of the trail for the dark hours. Run Management does its best to provide an adequately marked trail, but it is necessary for runners to continually remain alert as they travel. On occasion, persons not associated with the event have altered or removed course markings, or Run management cannot place signage at a critical turn on Run day due to unusual circumstances. A working knowledge of the trail, particularly of those miles that will be covered in the dark, will be of infinite benefit to the runner who attempts the Western States Endurance Run. YOU are ultimately responsible to follow the correct course.
8. Drops: If you have to drop out of the Run at a point where your crew is unavailable, we will make every reasonable effort to get you to the finish or to the nearest major checkpoint that is still in operation, particularly if you are in need of medical attention. In non-emergency situations, you may have to wait several hours before being evacuated. Runners having to drop from the Run BEFORE the Foresthill aid station will be taken to Foresthill. Runners having to drop AFTER Foresthill will be taken to the finish line. Our principal responsibility is to put on a Run, not to run a shuttle service for non-finishers; so please be patient. Aid stations will close when the sweeps arrive.
9. Trail Etiquette: Please be courteous to hikers, other runners and horsemen. Collisions on these narrow trails may be disastrous. If you wish to pass another runner, ask for “trail right” or “trail left” before attempting to pass. Slower runners must yield the trail to runners wishing to pass. Horses may be spooked by the sudden appearance of a runner, with serious consequences to the rider. Stop and step off the trail to let oncoming horses pass. Runners should never pass a horse from behind without first notifying the rider.
10. Volunteers: Approximately 1,500 dedicated volunteers help out at each Western States Endurance Run. They are truly the life-blood of the Run and will do everything possible to make your day a success. Many spend more hours out on the trail than do the runners themselves. Please be polite and make a point to thank them. Without the volunteers, there would be no Western States 100.