Western States 100 is a 100 miles ultra marathon in Olympic Valley, United States. Distance: 161km. Elevation: 5,500m D+. Difficulty: brutal (Challenge Rating 55/100). DNF rate: 25%. Time limit: 30h. Surface: trail. Established 1974.
Western States 100
Olympic Valley, California, United States
"The original 100-miler. From snow-covered Sierra passes to scorching canyons in a single day."
The oldest and most prestigious 100-mile trail race — a point-to-point odyssey from the Sierra Nevada to the foothills of Auburn, California.
The Course
From Olympic Valley to Auburn, California through the Sierra Nevada and canyons. The course crosses snow-covered passes, traverses exposed ridges, descends into 40°C canyons, and involves multiple river crossings. The oldest 100-mile trail race in the world.
mountainous
point-to-point
26
2,736m
Runner Experience
Well-supported with 26 aid stations. Frequent access to food, drinks, and medical support throughout the course.
A legendary finish line atmosphere. Western States 100 is a bucket-list race with celebrations that match its reputation.
Race Day Weather
30°C
8° – 42°
25%
5%
Extreme heat in the canyons during the day, cold at high elevation at night. Temperature swings of 30°C+ are normal.
Stats & Records
1974
300
27:30:00
14:09:28
Jim Walmsley (2019)
17:09:33
Courtney Dauwalter (2023)
Entry
$410
November
instant
Lore & Trivia
Western States is the oldest 100-mile trail race in the world and the event that launched modern ultrarunning. It began in 1974 as a horse endurance ride — the Tevis Cup, a 100-mile crossing of the Sierra Nevada from Squaw Valley to Auburn. That year, Gordy Ainsleigh's horse went lame before the start. He decided to run it on foot instead, finishing in 23 hours and 42 minutes. The following year, more runners showed up. By 1977, the Western States Endurance Run was a standalone foot race. The course descends from 2,650m in the snowy Sierra to 335m in the Auburn heat, crossing 30,000 feet of cumulative gain and loss through some of California's most dramatic canyon country. The race passes through mining towns, across raging rivers (the famous river crossings are waist-deep in high snow years), and into the furnace of the American River canyons where temperatures exceed 40°C. The finish line at Placer High School in Auburn — where runners arrive to cheering crowds, cold towels, and a ceremonial belt buckle — is one of the most emotional scenes in endurance sports.
- ▸ Founded in 1974 after Gordy Ainsleigh ran the Tevis Cup horse course on foot.
- ▸ The oldest 100-mile trail race in the world.
- ▸ Sub-24-hour finishers receive a silver belt buckle; sub-30 finishers receive a bronze buckle.
- ▸ The course has 5,500m of climbing and 7,000m of descent — net downhill, but the descents destroy quads.
- ▸ River crossings at the American River can be waist-deep in high-snow years.
- ▸ Temperatures in the canyons can exceed 40°C (104°F) in the afternoon.
- ▸ The lottery acceptance rate is roughly 6% — one of the most competitive entry processes in ultrarunning.
- ▸ The finish at Placer High School track in Auburn is one of the most emotional scenes in endurance sports.
The forest is alive at 3am in ways you never imagined. You hear things. You see things. Some of them are real.
Western States isn't a race you run. It's a race that happens to you.
Notable Editions
The Horse That Went Lame
Gordy Ainsleigh's horse was unable to start the Tevis Cup horse endurance ride, so he ran the 100-mile course on foot in 23:42. This single act of stubbornness created the sport of 100-mile trail running.
The Jurek-Kilian Showdown
Timothy Olson shattered the course record in 14:46:44, but the bigger story was the field depth — an era-defining race that cemented Western States as the most competitive 100-miler on earth.
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Frequently Asked Questions
How long is Western States 100? +
Western States 100 is a 100 miles (161km) ultra marathon with 5,500m of elevation gain. The course is point-to-point on trail terrain.
How hard is Western States 100? +
Western States 100 is rated brutal with a Challenge Rating of 55/100 (Challenging). The DNF rate is 25%. Runners have 30 hours to finish.
How do I enter Western States 100? +
Must complete a qualifying 100-mile or 100K race within the qualifying period.. Entry is by lottery. Entry costs $410. with a maximum of 369 starters.
What is the weather like at Western States 100? +
Average temperature is 30°C (range 8°C to 42°C) with 25% humidity and a 5% chance of rain. Extreme heat in the canyons during the day, cold at high elevation at night. Temperature swings of 30°C+ are normal.
Are crew and pacers allowed at Western States 100? +
Crew access is allowed. Pacers are allowed after 93km.
What is the course record for Western States 100? +
The men's course record is 14:09:28 set by Jim Walmsley in 2019. The women's course record is 17:09:33 set by Courtney Dauwalter in 2023.
What is the average finish time for Western States 100? +
The average finish time is 27:30:00. About 300 runners finish each year. The DNF rate is 25%.
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