The Bighorn Trail Run: 100, 52, 32 & 18 Miles From Dayton
July 21, 2026 · 7 min read read · Wyo Stays Journal
The Bighorn Trail Run is held each June in Dayton, Wyoming — a two-day mountain ultra weekend with 100-mile, 52-mile, 32-mile, and 18-mile races through the Bighorn Mountains. Registration fills months ahead, so runners and crews plan travel and lodging long before the snow melts off the high country.
Officially it's the Bighorn Mountain Wild and Scenic Trail Run, and it has been part of this valley's calendar for decades. For one weekend, Dayton — a town of a few hundred people at the foot of the mountains — becomes the center of American ultrarunning. Drop bags stack up outside the community hall, headlamps bob down the canyon at two in the morning, and the finish area fills with families ringing cowbells for strangers. We watch it happen every year from fifteen minutes away in Sheridan, and it never stops being a little surreal.
This guide covers what each distance involves, how race weekend actually flows, and the part most first-timers underestimate: where to sleep, and how far away that bed should be.
What Are the Bighorn Trail Run Distances?
Four races share the weekend, all finishing in Dayton. The 100-miler is the headliner — a remote, technical out-and-back with more than 20,000 feet of climbing and a roughly 34-hour time limit, per the race's own course description. The shorter races start progressively higher in the mountains and run down toward town, which sounds gentle and is not: descending for hours on rocky singletrack is its own kind of work.
| Race | Distance | Start (historically) | Finish |
|---|---|---|---|
| 100 Mile | 100 miles, out-and-back | Tongue River Canyon, just west of Dayton (Friday) | Dayton |
| 52 Mile | 52 miles, point-to-point | High in the Bighorns, near the 100-mile turnaround (Saturday) | Dayton |
| 32 Mile | 32 miles, point-to-point | Dry Fork area, mid-mountain (Saturday) | Dayton |
| 18 Mile | 18 miles, point-to-point | Lower mountain trailhead above the canyon (Saturday) | Dayton |
Start locations and times shift slightly year to year, and shuttle logistics matter — most Saturday runners ride buses from town to their start in the early dark. Treat the table above as orientation and confirm the current year's details at the race's official site, bighorntrailrun.com, before you build your weekend around them.
How Does Race Weekend Actually Work in Dayton?
The rhythm is distinctive. Friday morning and midday belong to the 100-milers — check-in, briefing, then a start up the Tongue River Canyon in the afternoon heat. Friday night, the leaders are already deep in the mountains while their crews grab a few hours of sleep. Saturday belongs to everyone else: buses roll out before dawn, the shorter races funnel down the canyon through the day, and by afternoon the finish area is a full-blown festival — food, music, kids in the river, and 100-mile finishers arriving to the loudest cheers of the weekend, some of them well into Sunday morning.
Two practical notes locals will tell you. First, June in the Bighorns is genuinely unpredictable — the high country can hold snow, the canyon can hit 85 degrees, and both can happen in the same race. Second, cell service disappears fast once you leave the valley floor; crews should agree on meeting points, not on texting. Our guide to cell service in the Bighorn Mountains covers which stretches go dark.
The best hour of the whole year in Dayton is Saturday evening during Bighorn — half the town is on lawn chairs cheering for runners they've never met. — a Wyo Stays local
Altitude, Crewing & the Mistakes First-Timers Make
The races live between roughly 4,000 and 9,000 feet, and most entrants come from lower elevations. You can't fully acclimate in a weekend, but arriving two or three days early, hydrating aggressively, and sleeping low in Dayton or Sheridan takes the edge off. Our Bighorn Mountains altitude guide goes deeper on what elevation actually does to visiting lungs.
Crews and pacers should plan around long, slow drives on gravel forest roads to reach the accessible aid stations — and around the volunteers who run them. The aid stations are famously well-stocked and famously local: community groups and area businesses sponsor and staff them, and grabbing quesadillas at 3 a.m. from a rancher in a headlamp is part of the race's character. Thank them; this event runs on their hours.
The most common first-timer mistake isn't fitness — it's logistics. Runners book a bed 45 minutes from the start, discover check-in, briefing, drop bags, and shuttles all pull them toward Dayton, and spend race eve driving. Stay close, cook your own pre-race dinner, and let the weekend be simple.
Stay Nearby: Dayton & Sheridan Homes for Race Weekend
Race weekend is exactly what our Dayton and Sheridan homes are built for. A full kitchen for the pasta the night before and the breakfast at 3:30 a.m., laundry for the mud, real beds for the crew, and a driveway for the gear explosion. Dayton and Ranchester homes put you minutes from the start and finish; Sheridan homes add restaurants and groceries fifteen minutes down the road. June fills early — the race sells out, and so does the valley — so browse and book at book.wyostays.com — Book Direct — No Channel Fees.
Practical Tips
- Confirm current-year dates, start times, and shuttle plans at bighorntrailrun.com — details shift year to year.
- Book lodging the moment your registration clears; the valley's beds go about as fast as race entries.
- Arrive two or three days early if you can — altitude is kinder with a little lead time.
- Crews: download offline maps and set physical meeting points before leaving the valley floor.
- Pack for both winter and summer. June in the Bighorns can deliver each within a single race.
- If your dates are set, check live availability at book.wyostays.com before hotels are your only option.
FAQ: Race Weekend in Dayton
Q: When is the Bighorn Trail Run held?
A: It's held each June, run as a two-day weekend out of Dayton, Wyoming — the 100-mile race starts Friday and the 52, 32, and 18-mile races run Saturday. Exact dates change annually, so confirm the current year's schedule at the race's official site, bighorntrailrun.com, before booking travel or lodging.
Q: Where do runners stay for the race?
A: In and around Dayton, Ranchester, and Sheridan. Dayton puts you at the start and finish; Sheridan, about fifteen minutes away, adds restaurants, groceries, and more lodging inventory. Because the race draws entrants from across the country into a small valley, houses and hotel rooms are typically booked months ahead — reserve as soon as your entry is confirmed.
Q: Is the race weekend good for spectators and families?
A: Genuinely, yes. The Dayton finish area on Saturday feels like a small-town festival — music, food, kids playing in the river, and finishers streaming in from afternoon into the night. Watching 100-mile runners finish is moving even if you've never run a step. Bring lawn chairs, sunscreen, and a cowbell.
Q: How hard is the 100-mile course?
A: It's considered a serious mountain hundred: remote, technical, out-and-back terrain in the Bighorn Mountains with over 20,000 feet of climbing and a roughly 34-hour limit, per the race organization. Weather ranges from snow in the high country to summer heat in the canyon, sometimes in the same year's race.
Every June we watch this valley fill with people chasing something hard in beautiful country, and every June a few of them tell us the weekend converted them into regulars. Whether you're racing, crewing, or just coming for the cowbells, Wyo Stays — a licensed, insured Wyoming vacation rental brokerage at 151 W Brundage St in Sheridan, hosting since 2017 — can put a real house under your race weekend. Call (307) 312-9656 or start at wyostays.com.