Western States 100: Running Olympic Valley to Auburn on the World's Most Famous Trail

Somewhere in the American River Canyon on Saturday night, Jim Walmsley or someone trying to beat him will be running through darkness at 90°F toward a finish line that is still 30 miles away.

That is Western States 100. It begins in a ski resort basin at 6,200 feet above sea level and ends on a high school running track in Auburn, California, at 1,100 feet. The distance is 100.2 miles. The net elevation is a 5,000-foot descent, which sounds like an advantage until you have absorbed 18,000 feet of climbing across the Sierra Nevada's western slope and then run the American River canyons at temperatures that the June California sun produces without apology.

The race has been contested annually since 1977. It draws its route from the Tevis Cup equestrian endurance race that follows the same historical path — mule trails and mining tracks cut into the Sierra Nevada during the Gold Rush and later used by the Western States Trail. The course was not designed for running. It was designed for horses. The fact that it has become the world's most historically significant 100-mile running event is a kind of accident that nobody involved regrets.

The Course, Section by Section

The Start: Olympic Valley to Emigrant Pass (miles 0–4.5)

The start gun fires at 05:00 in the Palisades Tahoe ski resort base area. The first 4.5 miles climb 2,550 feet to Emigrant Pass at 8,750 feet — the race's high point, reached before sunrise on most years. The climb begins immediately. The trail is wide enough for the compressed field to spread naturally over the first mile; the thinning begins on the steeper terrain above.

Emigrant Pass at dawn with a clear Sierra sky and 370 athletes strung across the snowfields above the Tahoe basin is one of the more striking images in American trail running. For athletes in the race, it is also the first major decision point: how much of the climb do you run versus hike, and what does that cost in the first hour versus the final twenty miles.

The High Sierra Traverse: Emigrant Pass to Robinson Flat (miles 4.5–29.7)

The trail drops from Emigrant Pass into a section of high-Sierra terrain — granite slabs, meadows, exposed ridge traverses — that the race's training runs describe as technical but runnable. The terrain is mostly runnable. The altitude, at 7,000–8,500 feet for most of this section, is the variable that affects athletes differently depending on where they trained.

Key landmarks: Lyon Ridge (mile 11), the first exposed ridge section with views into the Granite Chief Wilderness. Red Star Ridge (mile 19.7), where the trail begins a sustained descent toward the lower Sierra. Robinson Flat (mile 29.7), the first major crew access point — a meadow at 7,867 feet where crews can see their athletes for the first time after the start.

Crew access: Robinson Flat. Accessible by a dirt road from Auburn; crews need to plan for 3–4 hours of driving and waiting. The meadow is large and the atmosphere civilised.

The Middle Sierra: Robinson Flat to Michigan Bluff (miles 29.7–55.7)

This section is where the race's character begins to assert itself. The trail drops through a series of canyon drainages — Deadwood Canyon, El Dorado Canyon — and begins accumulating the cumulative descent that will define the back half of the race. The canyons heat up significantly as the course loses altitude; temperatures in the canyon bottoms can reach 90–100°F by midday, even in late June.

Last Chance (mile 43) is where the trail drops most steeply into the canyon system. The descent from Last Chance to the Swinging Bridge crossing of the American River is 2,000 feet in approximately 3 miles — technical, rocky, and the beginning of the heat loading that the race is famous for.

Michigan Bluff (mile 55.7) sits on a ridge above the canyons. A Victorian-era gold rush town — more of a hamlet now, with several dozen residents and a summer road that becomes crew access on race day. The climb into Michigan Bluff from the canyons below is steep and exposed; athletes arriving here after noon are doing so in full Sierra heat.

Foresthill: The Race's Midpoint in Spirit (miles 55.7–62.0)

Foresthill (mile 62.0) is the largest aid station on the course and the point where crew and pacers are permitted to join athletes for the remainder of the race. The school parking lot that functions as the aid station is, on race night, one of the better places in American trail running to be if you want to understand what the sport asks at its most concentrated.

Athletes arrive here anywhere from late afternoon to early night. The ones at the front of the race are still moving efficiently but have absorbed 62 miles of Sierra terrain. The ones arriving after dark are in a different race — managing time cutoffs, managing heat recovery, managing whatever went wrong between Robinson Flat and here.

Pacers can join at Foresthill. The pacer role from mile 62 onward — through the night, into the canyons, across the river, up the final climbs — is the most immersive way to experience Western States without being in the race yourself.

The Night Section: Foresthill to the River Crossing (miles 62–78)

From Foresthill, the course descends the Cal Street road section before dropping into the California Loop trail — a technical section of forest singletrack above the American River canyon. The trail is well-marked and frequently run by training athletes during the year; on race night, headlamps and glow sticks from the front runners create a column of light in the darkness below Foresthill that crews watch from the aid station above.

Rucky Chucky (mile 78) is the river crossing. The American River ford is knee-to-waist deep depending on snowpack year. Volunteers staff the crossing with safety lines. Athletes wade across — no bridge — and continue on the far bank. Early-season crossings in big snow years can be thigh-deep and cold; 2026 conditions will depend on the Sierra's runoff.

The Final Twenty: River to Auburn (miles 78–100.2)

The race's last section climbs from the river to the Auburn Lake Trails (mile 85.2) — a sustained climb in the early morning hours that arrives when most athletes' legs have been in motion for 15–22 hours. The climb is not technically difficult. At this point in the race, nothing needs to be technically difficult.

Highway 49 provides pacer vehicle access at mile 93. From there, the course crosses Robie Point and drops into Auburn's canyon before the famous No Hands Bridge (mile 96.8) — a suspension footbridge over the North Fork American River that appears on most Western States photo essays and serves as the psychological confirmation that the finish is real.

The last section climbs through the Auburn canyon to the Placer High School track at 1,100 feet. Athletes finish on the track in front of their crews, families, and the spectators who have gathered through the night. The fastest men finish in 14 hours; some athletes are still on the course 30 hours later when the official cutoff closes.

How to Experience Western States

Run the race: The lottery opens each December. Approximately 7,000 athletes apply for roughly 370 spots. Previous runners who did not finish get a single automatic entry; everyone else enters a luck-based draw with improving odds over consecutive non-winning years. The wait to enter and complete Western States is, for many athletes, measured in years.

Crew and pace: Entry to the crew/pacing experience requires a runner in the race. The pacer access from Foresthill (mile 62) through the night is the most involved version — 38 miles of moving through a dark Sierra canyon alongside someone running their hardest sustained effort. There is no version of Western States spectatorship more immersive than this.

Volunteer: The race requires 1,500+ volunteers across 100.2 miles of mountain terrain. Aid station captains, trail crew, finish line workers. Apply through the Western States website; volunteer positions fill quickly and are in some demand from athletes waiting for their lottery number to come up.

Spectate: The practical spectator locations — accessible by road, worth the effort — are Robinson Flat (mile 29.7, morning), Foresthill (mile 62, afternoon/evening), and the Placer High School finish in Auburn (varies by finishing position). The finish track in Auburn allows open spectator access through the cutoff window; the overnight gathering there is one of the sport's better nocturnal social events.

Truckee, California — the closest proper town to the start. 10 minutes from Olympic Valley, with hotels, restaurants, and the infrastructure of a four-season mountain town. Crews staying in Truckee can drive to the start and reach Robinson Flat within a half-day.

Auburn, California — the finish city. Gold Rush history, foothills geography, and a post-race atmosphere that the town has been producing for four decades. Auburn is easy freeway access from Sacramento (45 minutes east on I-80). Staying in Auburn lets crews sleep after finishing at Placer High School without a long drive.

Tahoe City — if you want the lake. Lake Tahoe's north shore is 20 minutes from Olympic Valley; the lake setting makes for an excellent rest day or post-race recovery before leaving the Sierra. Accommodation here is higher-cost in summer.

When to Go

Late June is the race window, and late June in the Sierra Nevada is its best season: wildflowers at elevation, snowmelt creeks still running through the canyons, days at 80–90°F in the valley with cool nights above 6,000 feet. The canyon sections can hit extreme temperatures even in June — heat management is a genuine race skill, not an afterthought.

Training visits: The Western States course is on public land and open year-round. The trail sections are marked on CalTopo and on the Western States Trail maps available from the race organisation. Key sections — the Cal Street/California Loop from Foresthill, the No Hands Bridge approach, the Robinson Flat meadow — are popular with Bay Area and Sacramento-area runners for training days. Snow closes the high Sierra section typically from December through May.

Frequently Asked

How do I enter the lottery? Applications open on the Western States 100 website in December, with results announced in early December. First-time lottery entrants have roughly a 6–8% draw rate; odds improve with consecutive non-selection years up to a guaranteed entry after multiple failed draws.

What is the golden buckle? Finishing under 24 hours earns the gold buckle — the race's iconic finishing award. The silver buckle goes to all official finishers under the 30-hour cutoff. Most starters who reach Foresthill finish; most DNFs occur in the canyon sections before mile 62.

Is pacing free to enter? Pacing is not competitive entry — it requires a runner already entered in the race. Runners must register their pacer through the race organisation. Pacers receive aid station access and a finish-line credential; the work is entirely voluntary.

How does the heat compare to other summer 100s? The American River canyon section in late June regularly exceeds 90°F. High-end pre-cooling protocols, crew ice at every accessible point, and early-morning canyon crossings are standard race strategy. Athletes arriving at the canyon sections later in the day face more sustained heat than those who ran conservatively in the Sierra above.

Where can I find training partners for Sierra ultra prep? Connect with athletes training in the Tahoe and Auburn areas via Find Crew in the Sierra Nevada on ZealZag.

For the elite field breakdown and Saturday's starting lineup, see our Western States 100 pre-race field report.