bighorn trail 100


Course Description


  The Bighorn Trail 100 Mile Run is an arduous trail run that will take place in the Little Bighorn – Tongue River areas of the Bighorn National Forest. Starting time for the event will be 10:00 AM Friday, with a 34 hour (average pace of 2.94 mph) time limit to finish the event. Runners must be prepared for potential extreme temperature variation and weather conditions during the event. Temperatures can exceed 100 degrees Fahrenheit during the day in the canyons and well below freezing at night in the mountains. The course is a wild and scenic traversing territory inhabited by elk, deer, moose, bear, cougars, mountain lions, and rattlesnakes with the potential for wildlife encounters with runners. Crew access points on sections of the course are limited and the runner should be prepared to carry  necessary equipment to ensure their ability to safely traverse difficult, remote, mountainous trails in potentially unpredictable weather conditions. The course is an out-and-back consisting of 76 miles of single track trail, 16 miles of rugged double track jeep trail, and 8 miles of gravel road with approximately 17,500 feet of climb and 18,000 feet of descent.        

      The starting point of the course is on the Tongue River Canyon road approximately 1.25 miles from the Tongue River Canyon trail head of trail #25 and approximately 3.5 miles from Dayton at the Tongue River fishing access parking area. Access to the start will be along the Tongue River Canyon road from Dayton. It is reccomended that participants as well as spectators take the shuttle bus to the start as there is very limited parking along the narrow canyon road near the start. Runners  proceed westerly along the gravel Tongue River Canyon road to the Tongue River Canyon trail head of trail #25. Participants then ascend Tongue River Canyon on trail #25 climbing out of the canyon on an intersecting trail to Horse Creek Ridge. Runners then descend into the Sheep Creek drainage on the trail crossing Sheep Creek to access 4-wheel drive Road #198. They will proceed westerly in the Sheep Creek drainage along trail and 4-wheel drive road #201 to access road #168 (Freeze Out Road) at the head of Camp Creek. Crossing road #168, they descend the Camp Creek drainage on trail and gravel road #168 to the intersection of 4-wheel drive road #149 with road #168 (head of the Dry Fork). Runners then descend the Dry Fork drainage along 4-wheel drive road #149 to its intersection with trail #4 (Dry Fork Trail) at Miller Creek. Runners continue northerly on trail #4 to cross the Little Bighorn River footbridge at the intersection of trail #4 with trail #50 (Little Bighorn Trail). From that point (Little Bighorn River footbridge),  runners will ascend the Little Bighorn River drainage on trail #50 crossing road #14 (Devil’s Canyon Road) and descend the Porcupine Creek drainage following the trail to the turn-around point at Jaws trail head. The runners subsequently return in the opposite direction on the same course to the starting point in the Tongue River Canyon. From that point, runners  continue to descend the gravel Tongue River Canyon road to the finish at Scott Park in Dayton.

         The elevation at the starting point of the Bighorn Trail 100 is approximately 4090 feet with runners ascending the Tongue River drainage to Horse Creek Ridge at approximately 7450 feet at 7.5 miles (first 1.25 miles of rough gravel road, then 6.25 miles of trail). Runners then descend on the trail to the Upper Sheep Creek crossing at approximately 7450 feet at 8 miles and continue 1/4 mile to the fully supplied Upper Sheep Creek Aid station. The course subsequently ascends in a rolling fashion (3 miles trail, 1.25 miles 4- wheel drive trail/road) to Camp Creek Ridge at approximately 7854 feet at 12.25 miles. Participants then descend (0.5 miles trail, 0.75 miles gravel road) to the first crew/drop bag aid station at approximately 7480 feet at the Freeze Out Road saddle of Dry Fork Ridge at 13.5 miles. Subsequently, the course descends the Dry Fork drainage on a primitive 4-wheel drive jeep trail in a rolling fashion to the fully supplied Kern’s Cow Camp Aid station at approximately 6600 feet at 19.5 miles. The course continues on the east face of the Dry Fork Canyon on a scenic, rolling trail to Bear Hunting Camp with limited supplies at approximately 6800 feet at 26.5 miles. Runners then descend on a steep trail into the Little Bighorn Canyon to cross the Little Bighorn River on a footbridge at approximately 4590 feet at 30 miles (a fully supplied crew/drop bag aid station point). The course then ascends 3.5 miles on trail to Cathedral Rock, a limited aid station, then continues through the scenic Little Bighorn Canyon passing by Leaky Mountain to Spring Marsh at approximately 6920 feet and 40 miles. Runners continue to ascend via trail through the Wagon Box Creek, Duncum Creek, and then into Elk Camp, a limited supply aid station. The course then continues to Willow Creek drainage to cross Devil’s Canyon Road on the Bighorn Mountain divide at approximately 8951 feet and 47 miles. The course then descends the Porcupine Creek drainage (0.5 miles trail, 0.5 miles jeep trail) to a turn-around point at JawsTrailhead (a fully supplied crew/drop bag aid station) at approximately 8800 feet and 48 miles.

      Runners return on the same course crossing the Bighorn Mountain divide at the trail crossing of Devil’s Canyon Road at 49 miles, descending by Spring Marsh at 56 miles, and continuing to descend to the Little Bighorn River footbridge at 66 miles (a crew/drop bag aid station). The course then ascends the Dry Fork drainage going through Bear Hunting Camp at 69.5 miles, Kern’s Cow Camp at 76.5 miles, and exits the Dry Fork Drainage at the Freeze Out Road saddle of Dry Fork Ridge (a crew/drop bag aid station) at 82.5 miles. Participants ascend to Camp Creek Ridge at 83.75 miles, descend the Sheep Creek drainage to the upper Sheep Creek crossing at 88 miles, and summit Horse Creek Ridge at 88.5 miles. The course then descends the Tongue River Canyon drainage to the Tongue River Canyon Road trailhead at 94.75 miles. Runners then descend the gravel Tongue River Canyon Road 1.25 miles going past the starting point of the race. Runners continue to descend on the Tongue River Canyon Road an additional 3.5 miles to Dayton crossing the Tongue River on a footbridge adjacent to U.S. Highway 14. They then cross U.S. Highway 14 in Dayton to finish 0.5 miles later at Scott Park in Dayton.

      Trail markings will consist of frequent orange flagging tape attached to trees, bushes, and rock. Some orange flagging tape will be attached to wire ground  flags in meadow areas. White powder arrows (made from lime) will be used at a few junctions on the course. Some of the orange flagging may have reflective tape applied to aid in visualization of the ribbon when traversing the course during the night. There will be occasional glow sticks used on the section of the course between Kern’s Cow Camp and Jaws trail head. Elk have been known to devour the markings on sections of this course in the past within 48 hours of the markings having been placed, despite the best efforts of race management.

    The race committee reserves the right to respond to potential safety contingencies posed by potentially adverse weather conditions or other course conditions to make "last minute" course changes. If any such course changes are required, runners will be fully briefed at the Friday pre-race briefing.

Upper Tongue River Canyon Trail

Upper Tongue River Canyon Trail

Aid Station Information


Outbound Aid Stations

Start ~ 10:00AM

Mile 0 - Tongue River Road

Elevation 4275'    Moderate Assistance  Crew and Spectators allowed    

Tongue River Trail Head ~ 10:25AM Cutoff

Mile 1.25

Elevation 4240'   Minimal Aid - Water only    No Crew/Pacers 

Upper Sheep Creek

Lower Sheep Creek~ No Cutoff

Mile 3.5  Elevation 5025'    

Minial Aid - water, hydration drink, trail mix, pretzels, 

granola bars, candy, nuts. 

No Crew/Pacers    

Upper Sheep Creek - No Cutoff

Mile 8.5  Elevation 7450'

Minimal Aid-water, hydration drink, trail mix, pretzels, 

granola bars, candy, nuts, fresh fruit. 

No Crew/Pacers     


Dry Fork Ridge ~ 3:00PM Cutoff

Mile 13.5  Elevation 7480'   

Major Aid - water, hydration drink, Meat and cheese roll ups, 

sandwiches, chips, fresh fruit, soda, cookies, candy, nuts, 

jerkey, special items.  

Crew Allowed- Parking Area 1/4m from Aid Station

Drop Bags Station

Kern's Cow Camp

Mile 19.5  Elevation 6600'

Moderate Aid - water, hydration drink, trail mix, pretzels,

 granola bars, candy, nuts, fresh fruit.    

 No Crew/Pacers

Bear Camp

Mile 26.5 Elevation 6800'   

Minimal Aid- water, hydration drink, pretzels, 

granola bars, candy, nuts.

 No Crew/Pacers

Sally's Footbridge ~ 8:30PM Cutoff

Mile 30   Elevation 4590'    

Major Aid

Crew/Pacers Allowed    

Medical Check 

Drop Bags Allowed

Parking Area 1/2m from Aid Station

Cathedral Rock

MIle 33.5 Elevation 5080'   

Minimal Aid -  water, hydration drink, pretzels, 

soup, granola bars, candy, nuts.

No Crew/Pacers

Spring Marsh

Mile 40

Elevation 6920'    Moderate Aid    No Crew/Pacers

Elk Camp

Mile 43.5

Elevation 7430'    Minimal Aid  No Crew/Pacers

Jaws Trailhead TURN AROUND 4:00AM Cutoff

Mile 48

Elevation 8800'    Major Aid Crew/Pacers Allowed    Drop Bags Allowed

Medication Check

Inbound Aid Stations

Elk Camp

Mile 52.5

Elevation 7430'    Minimal Aid   No Crew/Pacers

Spring Marsh

Mile 56

Elevation 6290'    Moderate Aid    No Crew/Pacers

Cathedral Rock

Mile 62.5

Elevation 5080'    Minimal Aid    No Crew/Pacers

Sally's Footbridge ~ 10:00AM Cutoff

Mile 66

Elevation 4590'    Major Aid    Crew/Pacers Allowed   Drop Bags Allowed

Medical Check

Bear Camp

Mile 69.5

Elevation 6800'    Minimal Aid   No Crew/Pacers

Kern's Cow Camp

Mile 76.5

Elevation 6600'    Moderate Aid    No Crew/Pacers

Dry Fork Ridge ~ 3:00PM Cutoff

Mile 82.5

Elevation 7480'   Major Aid    Crew/Pacers Allowed    Drop Bags Allowed

Medical Check

Upper Sheep Creek ~ 4:30PM Cutoff

Mile 87.5

Elevation 7450'   Moderate Aid    No Crew/Pacers

Lower Sheep Creek

Mile 92.5

Elevation 5025'    Minimal Aid    No Crew/Pacers

Tongue River Trail Head ~ 6:45PM Cutoff

Mile 94.8

Elevation 4240'    Moderate Aid    Crew by BIKE ONLY  


Home Stretch

Mile 98

Elevation 4040'   Moderate Aid   Crew by BIKE ONLY


Mile 100

Elevation 3970'    Major Aid    Drop Bags Allowed  

100 Mile Start 2018

100 Mile Start 2018

Medical information


 All runners will be weighed at the race packet pickup and will be asked for updated medical information that might be germane to their participation in this race. The starting weights will be recorded along with pertinent weight parameters and significant medical information. Periodic medical checks of the participants consisting of mental acuity assessments will be performed at designated medical checkpoints during the event (Jaws Trailhead, Sally's Foot Bridge and Dry Fork checkpoints). Mental alertness will be screened at all manned aid stations.

       If the medical personnel flags a runner whom they are concerned about, a full medical check will ensue. This will consist of weight, blood pressure, pulse, oxygen saturation, and respirations as well as a thorough physical and mental assessment by a medical professional. A weight loss of 3% indicates that significant dehydration has occurred and the runner will be encouraged to hydrate back to their pre-race weight. At 5% weight loss, the runner may be nearly exhausted and may be held by the aid station until adequate hydration can be established by the runner. A 7% loss of body weight may be grounds for mandatory withdrawal from the race due to the high risks of heat exhaustion or hypothermia while on the course and the increasing risk of dangerous impairment of bodily functions. These decisions will be made by our qualified medical professionals.

      Weight gain may also be problematic indicating retention of water with the corresponding risk of dilutional hyponatremia and possible seizures. Runners over 3% of their starting weight will be queried further regarding their fluid intake and urination history with particular attention directed to a participant who has not been urinating during the event. Runners over 5% of their starting body weight may likely be held for closer monitoring and possible mandatory withdrawal from the race due to the risks of hyponatremia and seizures from excessive water retention during an ultramarathon event.

       It is important for the participant to recognize the potential physical and mental stresses, which may evolve from participation in this race. The runners may be subject to extreme temperatures of heat and cold, hypothermia, heat stroke, kidney failure, seizures, low blood sugar, disorientation, injury, falling rock or trees, wild animal or reptile attack, or even death from their participation in this event.

       Adequate pre-race conditioning is mandatory and a participant should not run the race if they have not been able to prepare adequately to run safely. Hypothermia and heat illness will be significant risks in this race. Both can cause nausea, dizziness, and mental confusion. Impending heat stroke may be signaled by a decrease in sweating and goose bumps and can progress to collapse in a short period of time. The diagnosis of why a runner is nauseated requires careful consideration of temperature conditions at the time of illness, altitude, and race pace to arrive at corrective measures. Proper race pace is crucial. A runner must be careful not to exceed their own physiologic  thresholds which may vary according to temperature, altitude, terrain, and conditioning. High altitudes above 7000 feet coupled with strenuous exertion may produce various degrees of altitude sickness. This can lead to severe lung and brain swelling which without treatment can even lead to death. Treatment for altitude sickness is rest and descending to a lower altitude. Altitude sickness can be prevented with altitude acclimation, proper fluid and electrolyte intake, and proper pace.

       Injuries from falling both on even or rough trail, hazards of running in possible snow conditions, falling rock or trees, and injuries related to adverse encounters with wildlife exist for the participant taking part in this race. Vehicle hazards, common fatigue, getting lost, and being far from medical help, treatment, and evacuation are just some of the other risks associated with participating in the Bighorn Trail 100. It is crucial that the runner has physically prepared himself/herself to safely participate in this race, stays mentally alert, stays adequately hydrated and nourished during the event, and is mentally prepared  to withdraw at an appropriate time if he/she can not safely continue.


      All participants will be checked in by their race number/bib at the start of the race by race management and will be checked in/out of all manned aid station checkpoints along the course. Sheridan Search and Rescue will provide communications support at all the manned aid stations. The communications personnel will be provided an accurate list of all starters and their race number. Each participant will have a check in/check out time recorded at each manned aid station with the information radioed to the next aid station to aid in accounting for each runner during the event. In the event a runner has failed to check in/out of the next manned aid station, a trail sweep will be conducted at the appropriate time along each section of the trail. If the sweep fails to account for any runners, race officials will notify standby groups for an emergency search. If an emergency search is activated, any emergency search costs will be the responsibility of the entrant including any emergency search costs  generated by the entrant failing to properly withdraw from the event by turning in their race number to the Aid Station captain at the closest aid station.

Dryfork Area

Dryfork Area

CREW information


 Crew access locations during the event include the starting point, Camp Creek Ridge intersection with Freeze Out Road (out only), Dry Fork Ridge Aid Station (out and in), Sally's Footbridge Aid Station (out and in), Little Bighorn Trail course intersection with Devil’s Canyon Road (out and in), Jaws Trailhead, and from the Tongue River Canyon Trailhead to the Finish . Detailed crew access directions will be available at the packet pick-up and rules regarding crew access at specific crew access locations will be reiterated. Crew access from the Tongue River Canyon Trailhead (94.75 miles) on Tongue River Canyon Road to the Finish will only be by foot or bike because of congestion on Tongue River Canyon road. Crew access to Dry Fork Ridge Aid Station (in) on Saturday will have parking restrictions.

        Crew access to Sally's Footbridge Aid Station (out and in) is difficult due to the distance to the mouth of the Little Bighorn River Canyon and the fact that there is limited parking in the canyon. Crews should expect at least 25 minutes to navigate the 2 mile section of rocky, rough, primitive road into the canyon to the designated crew parking area. From that crew parking area, crews will need to walk ¾ miles to access Sally's Footbridge Aid Station. A high clearance vehicle is recommended for accessing Sally's Footbridge Aid Station and carpooling is suggested. It will take a crew approximately 2.5 hours, at a minimum, to go between Dry Fork Ridge Aid Station and the Footbridge Aid Station both out and in.

       Approximate travel times that should be considered by entrants and their crews assuming good road conditions and no construction delays are as follows:

  • Start to Camp Creek Ridge (12.25 miles) 1.25 hours by car
  • Camp Creek Ridge to Dry Fork Ridge (13.5 miles) 5 minutes by car
  • Dry Fork Ridge to Sally's Footbridge Aid Station (30 miles) 2.5 hours by car + ¾ mile shuttle/walk  (good clearance auto needed last 2 miles)
  • Sally's Footbridge to Course x’ing of Devil’s Cyn Road (47 miles) 2.5 hours by car +¾ mile shuttle/walk out
  • Devil’s Cyn Rd x’ing to Jaws Trailhead (48 miles) 10 min by car
  • Jaws Trailhead to Devil’s Cyn Rd x’ing (49 miles) 10 min by car + 1/3 mile walk out
  • Devil’s Cyn Rd x’ing to Footbridge Aid Station (66 miles)  2.5 hours by car + ¾ mile shuttle/walk in
  • Sally's Footbridge to Dry Fork Ridge Aid Station (82.5 miles) 2.5 hours by car + ¾ mile shuttle/walk out
  • Dry Fork Ridge to Scott Park Finish Area (100 miles) 1.25 hours by car

      Crews may provide aid to their runner at any point on the course after the Tongue River Canyon Trailhead (94.75 miles) to the finish as long as they have not driven on the Tongue River Canyon Road to access their runner. They may walk, run, or bike on the Tongue River Canyon Road to access their runner and must return via the same manner. Crew or family who drive a vehicle on Tongue River Canyon Road will subject their runner to disqualification.


  1. To the 100 mile start: The entrance to the Tongue River Canyon Road is on the northeast side of the Tongue River Bridge on Hwy 14 as a driver enters Dayton heading west from Ranchester. Take the Tongue River Canyon Road proceeding upstream on the northeast side of the Tongue River. Go left at a junction approximately 2.5 miles from Dayton and proceed on the Tongue River Canyon Road approximately 1 mile further to the Amsden Fishing Access area in the Tongue River Canyon (a primitive outhouse will be noted on your right). The start will occur on the Tongue River Canyon Road by the big cottonwood tree where the road turns toward the north wall of Tongue River Canyon at the west end of the fishing access area (approximately 1.25 miles from the Tongue River Canyon Trailhead).
  2. To the Head of the Dry Fork (Dry Fork Ridge): Take Hwy 14 from Dayton and proceed up the mountain to Burgess Junction. At Burgess Junction, take a right on Forest Service Road #15 (Dayton Gulch Road) proceeding past Burgess Ranger Station and eventually crossing Fools Creek at approximately 5 miles. Shortly after crossing Fools Creek, take a right on Forest Service Road #168 (Freeze Out Road) and proceed approximately 5 miles to the head of the Dry Fork Aid Station which is located at the intersection of Forest Service Road #149 and Forest Service Road # 168 (Freeze Out Road).
  3. To Sally's Footbridge Aid Station in the Little Bighorn River Canyon: From Dayton, cross the Tongue River Bridge at the eastern aspect of town and turn north on Wyoming Hwy 343 proceeding 5.2 miles to the intersection of Wyoming Hwy 345 (old US Hwy 87). Turn left on Wyoming Hwy 345 and proceed past Parkman, WY, going into Montana at 5.9 miles where you enter the Crow Indian Reservation and continue on this highway until you reach the Littlehorn Road just south of Wyola, MT, at 15 miles. Turn left on the Littlehorn Road, cross the railroad tracks and proceed west on the Littlehorn Road toward the Bighorn Mountains crossing the Little Bighorn River at 9.7 miles, having the pavement change to gravel at 10.5 miles, crossing the Little Bighorn River at 12 miles, and encountering a cattle guard at a 4-way junction at 15.85 miles. The 4-way junction has a sign by the cattle guard, erected by the Wyoming Game and Fish Dept, which is brown and states the road going past the cattle guard provides public access through private lands, please stay on established roads. Proceed through the cattle guard, taking this primitive road into the mouth of the Little Bighorn River Canyon. You will ford a creek at 0.45 miles, ford a second creek at 0.6 miles, reenter Wyoming at a primitive sign noting that you are at 45 degrees Latitude, and cross the Little Bighorn River on a bridge at 1.5 miles. Continue on the northern side of the Little Bighorn River where you will encounter an area where we wish crews to park at approximately 2.5 miles. Be careful not to block the road when parking and do not block the private bridge crossing to the cabins on the south side of the Little Bighorn River when parking in this area. Park well off the road; but be careful you don’t high center your vehicle on scattered rocks in this parking area. Parking is very limited further up the canyon and is reserved for aid station/emergency access vehicles. After parking, proceed by foot approximately ¾ mile distance from the designated parking area up the canyon on the primitive road to reach the Footbridge Aid Station. You will go past the Wyoming Game & Fish Patrol Cabin area shortly before you encounter the Footbridge Aid Station.
  4. To Devil’s Canyon Road Crossing: Take Hwy 14 from Dayton and proceed up the mountain to Burgess Junction. Take Hwy 14A from Burgess Junction towards Lovell approximately 18.7 miles and turn right on Devil’s Canyon Road (previously known as Sheep Mountain Road). Go north approximately 2 to 2.5 miles to where the 100 mile course crosses Devil’s Canyon Road.
  5. To Jaws Trailhead: Take Hwy 14 from Dayton and proceed up the mountain to Burgess Junction. Take Hwy 14A from Burgess Junction towards Lovell for approximately 20.7 miles to turn right on Forest Service Road #13 which is just prior to the road going to the Medicine Wheel and is just prior to Hwy 14A starting to descend off the mountain. Go on Forest Service Road #13 in a northerly direction proceeding past Porcupine Campground on your left at approximately 1.9 miles. Cross over Porcupine Creek and continue driving past the entrance to the Porcupine Ranger Station (do not drive into the entrance of Porcupine Ranger Station).  Proceed left up the hill past the entrance to Porcupine Ranger Station for about ¼ mile where you will turn left into the parking lot for Jaws Trailhead at approximately 2.5 miles.  Park in the designated areas for crew in Jaws Trailhead or as otherwise directed keeping the entrance to Jaws Trailhead clear for traffic and runners.



Pacer information


A pacer is any individual who accompanies a runner for a distance greater than 100 yards

  • Pacers are only allowed to accompany 100M runners. There are no pacers allowed for the 52M, 32M or 18M distances.
  • One pacer at a time may accompany each 100M runner starting from Sally's Footbridge Outbound (mile 30), Jaws Trailhead (Turn-around, mile 52), Sally's Footbridge Inbound (mile 66), and Dry Fork Ridge Inbound (mile 82.5).An entrant over the age of 60 or with special medical conditions (MUST be cleared by the Race Director in advance by April 30th) may be paced from the start.
  • Vehicles are not allowed on Tongue River Canyon Road from the Trailhead to the finish at Scott Park. We encourage you to meet your runner by either walking, running, or biking on the road. A crew runner may accompany the competitor on the final course section into the park, but must only do so on foot, or on a bike.
    Each pacer must sign a waiver release prior to pacing a runner. These will be available at packet pick-up, the pre-race briefing and from the aid station captain at Sally's Footbridge, Jaws trailhead and Dry Fork Ridge. Crew/Pacer vehicles on Tongue River Road subject their runner to disqualification.
  • Pacers must be at least 18 years of age. Specific exceptions to the age requirement may be made in advance of the race by the Race Director with a guardian’s signature.
  • Each pacer must wear the official pacer bib of the entrant he/she is pacing. One pacer bib is provided per entrant at race check in. The official pacer number must be transferred between pacers if duties for one runner are to be shared. If a pacer becomes unable to continue the race, the official pacer number must be given to the runner, so that subsequent pacers will be properly identified. Pacer bibs are available at packet-pickup or from the aid station captains at Sally's Footbridge, Jaws Trailhead and Dry Fork Ridge.
  • Each pacer must clearly identify themselves when passing through checkpoints so that race personnel know exactly who is on the trail and where. Pacers must stay with their runners at all times, except in the case of emergency. If the runner withdraws from the race, and the pacer wishes to continue, the pacer must remain at the Aid Station until another runner enters the Aid Station and requests the services of a pacer. The pacer may not continue on without an official race participant.
  • Pacers must enter (CHECK IN) and leave (CHECK OUT) each Aid Station WITH their runners. Runners are to carry their own supplies and pacers are to carry their own supplies. No mechanical or physical assistance may be given by the pacer to the runner at any time.

Father with PACER son finishing the 100 mile  race

Father with PACER son finishing the 100 mile race