Overview
Lost Horse Creek Trail accesses a quiet corner of the Bitterroot National Forest southwest of Hamilton, Montana, where the canyon sees far fewer visitors than Blodgett or Bass Creek. The 7.2-mile out-and-back follows Lost Horse Creek through old-growth western larch and Douglas fir, entering the Selway-Bitterroot Wilderness at the upper end of the maintained trail.
The Lost Horse drainage is prime elk country. The upper meadows beyond the wilderness boundary support a resident elk herd, and even the lower canyon shows heavy elk sign through summer and fall. Western larch, which turns vivid gold in October before dropping its needles, dominates the middle canyon and makes this one of the best fall color destinations in the Bitterroot.
The Route
Trailhead to Lower Canyon (0 to 1.5 miles)
Lost Horse Creek Trail begins in open ponderosa forest and quickly transitions to mixed conifer as the canyon narrows. The trail follows the creek closely and several easy access points allow water filtering for those making the full trip. The first mile and a half is the gentlest section, well-suited to establishing a pace.
Middle Canyon Larch Zone (1.5 to 3.0 miles)
Western larch dominates this section and the forest floor opens below the high canopy. The trail gains more steadily as the drainage narrows. In October, the gold of the larch needles fills the canyon with a warmth that persists even on overcast days. Elk sign is consistent through this zone: tracks, rubs on young trees, and wallows near the creek all signal high use by the resident herd.
Upper Canyon and Wilderness Boundary (3.0 to 3.6 miles)
The trail climbs to the Selway-Bitterroot Wilderness boundary through increasingly remote terrain. A series of open meadows in the upper canyon provides views of the surrounding ridges. The wilderness boundary marks a natural day-hike turnaround. Backpackers continuing inside the wilderness should be prepared for unmaintained trail and navigation by map and compass.
When to Hike
June and July allow access after snowmelt with good water flow in the creek. The lower larch forest is green and the upper meadows are coming into bloom. Creek crossings are straightforward for most of the season.
August and September are reliable with dryer conditions and improving solitude as summer crowds thin. Wildlife activity increases through September as elk begin their rut in late September.
October is the standout month for fall color seekers. The western larch turns a saturated gold that peaks in the first two weeks of October, making this the most visually spectacular time to visit. Snow is possible at the wilderness boundary by mid-October.
What to Bring
Many hikers carry 2 liters of water for this length of route, with creek water filtered as a supplement. Bear spray is strongly recommended in this drainage, which sits in documented grizzly bear territory. See our guide on bear canister requirements if you plan to camp overnight.
Layers are valuable for the upper canyon, which holds cool air in the mornings. In October, bring warm clothing for the return in afternoon shade. Trekking poles help on wet trail surfaces after rain.
Trailhead Access
The Lost Horse Creek Trailhead is on Lost Horse Road, accessed via the West Fork Road (Highway 473) southwest of Hamilton. The road is gravel for the final miles to the trailhead. No permit or parking fee is required (as of 2026). A vault restroom is present.
Dogs are welcome on this trail, which sees low enough traffic that off-leash dogs can be managed safely in the lower canyon. Keep dogs under control near creek crossings during spawning periods.
Nearby
Lost Horse sits in the West Fork corridor with Trapper Peak Trail accessible from the same road. Tin Cup Lake is another Selway-Bitterroot wilderness-adjacent destination in this southern portion of the forest. Blodgett Canyon and Bass Creek to the north offer contrasting canyon experiences with more services nearby.
Check the USFS conditions guide for current fire restrictions and road conditions on the West Fork corridor. Follow Leave No Trace principles throughout.