Guides/Overland routes/Idaho
Overland route46 midifficulty: moderate

Custer Motorway

RegionIdahoAgencyBureau of Land Management, U.S. Forest ServiceLast verified—
Custer Motorway — overland route near Stanley, Idaho, Idaho
Photo by Antonia Hedrick / BLM Idaho via Wikimedia Commons (public domain)
Trail vitals6 facts
Length
46mi
Technical difficulty
Moderate
Direction
Point to point
Vehicle
High-clearance vehicle. Not recommended for low-clearance vehicles or trailers.
Best months
Jun, Jul, Aug, Sep, Oct
Cell coverage
None on the route
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The Custer Motorway is a 46-mile dirt-and-gravel route through central Idaho's Yankee Fork drainage between Stanley and Challis, following the alignment of an 1879 toll road built by Alex Toponce to supply the Bonanza and Custer mining boomtowns. Both towns are now ghost towns within the Land of the Yankee Fork State Park, and the route passes the Yankee Fork Dredge — a 988-ton gold dredge that operated from 1940 to 1952 and is preserved on-site.

The motorway was reconstructed by the Civilian Conservation Corps in 1933. The road weaves through mountains and along the Yankee Fork river past stage stops, horse barns, and mining sites. Open after snowmelt; not recommended for low-clearance vehicles or trailers.

Hazards

Read before you go

  • Snow closure. The route closes from approximately November through May.
  • High elevation. The divide section sits over 8,000 feet. Visitors from sea level should expect altitude effects.
  • Wildlife. Mule deer, elk, mountain lions, black bears in the area.
  • Mining hazards. Open shafts and unstable structures at Custer and Bonanza. Stay on the marked routes.
  • Cell coverage. None along the motorway.
  • Wet weather. Heavy rain rutting on the climbing sections.

Location

46 mi · Overland route

Approx. location 44.213, -114.928

Trail facts

5 fields
AgencyBureau of Land Management, U.S. Forest Service
Nearest townStanley, Idaho
Websiteparksandrecreation.idaho.gov/state-park/land-of-the-yankee-fork-state-park
ClosedNov, Dec, Jan, Feb, Mar, Apr
Approx. location44.213, -114.928

Getting there

Directions

Southern access (Stanley). From Stanley on State Highway 75, drive 13 miles east to Sunbeam. Turn north on the Yankee Fork Road (Forest Road 013). The motorway runs north 46 miles to Challis.

Northern access (Challis). From Challis on US-93, head south to the marked Custer Motorway turnoff (Forest Road 070).

Approximate Stanley access coordinates: 44.213° N, -114.928° W.

Photos

1 photo

Photos · 1

Field notes

Getting Oriented

The motorway sits in central Idaho's Custer County, in the Salmon River Mountains. Stanley anchors the southern access, with Challis on the northern end. Both are small mountain service towns. The Land of the Yankee Fork State Park manages the historic mining sites along the route, including Custer (a ghost town and museum) and the Yankee Fork Dredge.

Trail Overview

The motorway leaves State Highway 75 at Sunbeam, climbs north through the Yankee Fork drainage past the Yankee Fork Dredge, continues through the ghost town of Custer, and tops out at the divide before descending to Challis on US-93. Surface conditions are graded gravel for most of the route, deteriorating to rougher dirt on the climbs near the divide. Driving the full 46 miles takes about three hours without stops; with stops at the dredge, Custer ghost town, and the various stage stops along the way, it's a full day.

Points of Interest

  • Yankee Fork Dredge. A 988-ton gold dredge that operated 1940-1952. Self-guided tours when staff is on-site.
  • Custer Ghost Town. Museum and preserved buildings from a 1877-1911 boomtown that peaked at 600 residents.
  • Bonanza Cemetery. Pioneer cemetery from the original boomtown.
  • Land of the Yankee Fork Interpretive Center. Museum at the southern end with mining history exhibits.
  • Stage stops and horse barns. Remnants of the original toll-road infrastructure scattered along the route.
  • Sunbeam Hot Springs. Natural hot springs on the Salmon River near the southern entrance.

Where to Camp

Multiple Forest Service campgrounds in the Yankee Fork drainage offer fee sites with vault toilets and water. Dispersed camping is allowed on the surrounding national forest land with the 14-day stay limit. Stanley and Challis have commercial campgrounds and lodging.

Tips for a Safe and Enjoyable Trip

  • Visit June through October. Snow closes the route the rest of the year.
  • Carry water; the route has no potable water beyond the campgrounds.
  • Cell coverage is absent. Carry an offline map.
  • Visit the Yankee Fork Dredge during state park operating hours for the guided tour.
  • Stay on designated routes. The Yankee Fork drainage is mining-history-rich; off-road damage destroys archaeological resources.
  • Watch for fishermen along the Yankee Fork — the river holds salmon, steelhead, and trout.
  • Contact the Land of the Yankee Fork State Park at 208-879-5244 for current conditions.

Frequently asked

Common questions

How difficult is Custer Motorway?
Custer Motorway is rated moderate. The route runs 46 miles.
What kind of vehicle do you need for Custer Motorway?
High-clearance vehicle. Not recommended for low-clearance vehicles or trailers.
When is the best time to visit Custer Motorway?
The best months are Jun, Jul, Aug, Sep, Oct. Avoid Nov, Dec, Jan, Feb, Mar, Apr.
Is there cell service at Custer Motorway?
None on the route