The 'Supercourse': a 100-mile loop from Jug Mountain Ranch over Ladybug and Jughandle Mountains and down to Louie Lake Dam, east to Lake Fork, up Fall Creek to South Crestline, then 17+ miles of high country along the Crestline (via the 45th Parallel goat aid station and Box Pass) to North Crestline, on to Upper Payette Lake, across to Duck Lake and Snowslide, back out to Lake Fork via an out-and-back, then a final climb over Boulder Summit and around Boulder Mountain to Boulder Lake Trailhead before descending to the finish at Jug Mountain Ranch.
"Very difficult. IMTUF is a Hardrock100 Qualifier for a good reason... The footing is rough overall and downright brutal at times. Finishers have often compared it to Wasatch 100 in difficulty, but more technical." A reported quote from the first two 2023 finishers: "harder than Hardrock...and the most technical 100 in the United States." Stats (RD's own words): "100+ mi, 22,000 gain. Approximates. We don't believe the technology exists to accurately measure the course or its vert." Course narrative describes several named passes in the 7,700-8,300+ ft range (Box Pass ~8,000 ft is called the Crestline's high point; Boulder Summit is described as "8,300+'" with the Boulder Mountain summit "about 500' above" that, i.e. roughly 8,800 ft) but the race does not publish an official high/low point figure, so high_point_ft/low_point_ft are left null here rather than asserted from prose approximations. Includes a mandatory WALK (no running) zone of about a quarter mile through talus below the Jughandle summit, and a ~1.4-mile out-and-back spur to Lake Fork Aid #2 (miles ~81 to 82.4 and back).
A 100-mile mountain loop race starting and finishing at Jug Mountain Ranch near McCall, Idaho, crossing multiple 7,000-8,300+ ft passes in the Salmon River Mountains with roughly 22,000 ft of climbing on rugged, TUF footing. A companion 20-mile race over Jughandle Mountain (the IMTUF 20 Mile) starts the following morning from the same venue. Both races together make up the Idaho Mountain Trail Ultra Festival (IMTUF).
First run in 2012; 2026 is the 15th running. The course ran clockwise in 2012 and switched to counter-clockwise in 2013. The current 'Supercourse' routing was introduced in 2020 and has been trimmed slightly at the start/finish in most years since (most recently losing about 1.5 miles in 2025 due to logging activity in the area); the 2026 course is planned to be identical to 2025. Since 2012 the race has run with permission from the Payette National Forest McCall Ranger District and the Idaho Department of Lands.
| Mile | Station | Cutoff | Crew | Bag | Pacer | Med | To next |
|---|---|---|---|---|---|---|---|
| 0.00 |
Jug Mountain Ranch (Start)
4,955 ft
|
? | ● | ● | · | ? | 10.40 |
| 10.40 |
Louie Lake Dam
7,008 ft
|
? | · | · | · | ? | 9.30 |
| 19.70 |
Lake Fork Aid #1
5,430 ft · cell service
|
2:00pm | ● | ● | · | ? | 9.80 |
| 29.50 |
South Crestline
5,575 ft
|
4:30pm | ● | ● | · | ? | 7.20 |
| 36.70 | 45th Parallel | ? | · | · | · | ? | 10.30 |
| 47.00 |
North Crestline
7,200 ft
|
10:45pm | · | ● | · | ? | 8.70 |
| 55.70 |
Upper Payette Lake
5,584 ft
|
1:15am | ● | ● | ● | ? | 10.40 |
| 66.10 |
Duck Lake
6,552 ft · no cell service
|
5:00am | · | · | · | ? | 4.65 |
| 70.75 |
Snowslide
5,915 ft
|
6:30am | ● | ● | ● | ? | 11.65 |
| 82.40 |
Lake Fork Aid #2
5,430 ft
|
10:30am | ● | ● | ● | ? | 11.60 |
| 94.00 |
Boulder Lakes Trailhead
6,234 ft
|
3:45pm | ● | ● | ● | ? | 5.80 |
| 99.80 |
Jug Mountain Ranch (Finish)
4,955 ft
|
6:00pm | ● | ● | ? | ? | ? |
From Boise: take Idaho Rt 55 north about 100 miles. At Lake Fork (4 mi south of McCall), turn RIGHT/EAST onto East Lake Fork Road, follow to the junction with Farm-to-Market Road, cross straight ahead and enter Jug Mountain Ranch (JMR) Golf Resort at their sign. For initial Friday check-in, park at the main JMR paved Clubhouse lot; packet pickup is at the Party Tipi tent just north of the Clubhouse. Camp/start-finish area is a little over half a mile north of the Clubhouse; the exact route in depends on time of day and the golf schedule (see JMR Driving Directions / First Fairway vs North Elk routes).
docs.google.comFrom JMR, take East Lake Fork Rd back to Rt 55 north towards McCall, then Lick Creek Road (reachable via the Ponderosa State Park route), past Little Payette Lake; it turns to dirt. When you cross a small bridge over Lake Fork Creek, the station is on the right.
Parking. Park on Lick Creek Road on the right side. Do not block traffic.
docs.google.comDrive back towards McCall on Lick Creek Rd, past Little Payette Lake. Go RIGHT on Eastside Drive, a few hundred yards then RIGHT on dirt Forest Road 1716 (sometimes written 716). Drive just over 1.0 mi to where a sign or attendant stops further travel; there is a minimum quarter-mile walk uphill to the station from there.
Parking. Park where directed below the last steep climb; the road is narrow and crews must use small pullouts so traffic can pass. "Ask yourself before you park: Can a big truck pulling a trailer with ATVs on it get past me on this tiny road?"
docs.google.com25 miles from South Crestline. Access via Warren Wagon Road heading north; at signs for Upper Payette Lake go LEFT on Forest Road 495 (drive SLOW, zero dust, runners share this road) for 2.4 mi to the dead end at the aid station.
Parking. Dead-end forest road parking at the aid station; drive slow, zero dust, runners share the road.
docs.google.comFrom Upper Payette Lake, drive back south to McCall or use the Eastside Drive shortcut to Lick Creek Road; once on Lick Creek Rd, drive past Lake Fork Aid and continue 4.5 mi further to Snowslide.
Parking. Park on the right; "this is the smallest and tightest parking situation on the course. Park smart."
docs.google.comDrive back towards McCall; easiest to return to town and take Rt 55 south then Lick Creek Road to the same Lake Fork Trailhead used for Aid #1.
Parking. Park on the right side of Lick Creek Road, not blocking traffic or the aid station.
docs.google.comDrive back towards McCall; take Rt 55 south to Elo Rd just south of town, which becomes Farm-to-Market Rd. On a big bend right, go LEFT on Boulder Lake Road (Forest Road 403, signed "Boulder Lake 5 miles"), paved then dirt then chunky gravel; multi-ply "LT" rated tires recommended, functional spare needed. Pass the McCall Zipline parking and continue; the road drops downhill for a few hundred yards to the trailhead.
Parking. Busy, popular trailhead with limited parking; park carefully and do not crowd out other trail users.
docs.google.comFrom Boulder Lakes Trailhead, drive back down Boulder Lake Road about 5 mi to the Elo Rd/Farm-to-Market Rd junction, go LEFT/SOUTH about 3 miles to the JMR entrance, then LEFT into JMR (route back to camp/finish depends on time of day and the golf schedule).
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