Lost Horse Pass - Bitterroot Mountains, Montana

Our second Bitteroot outing of the season started on July 21 at Upper Twin Lake, at the end of the Lost Horse Creek road, thirty miles southwest of Hamilton, at about 6500 feet elevation. Looking north across the lake, Lost Horse Pass is just above the far shore.
Following the main trail along the east shore, we soon can see our hiking goal for the day: Wahoo Pass, directly west of the lake and nearly 1000 feet higher
We stopped at Lost Horse Pass to admire the wildflowers in bloom. In addition to the yellow alpine daisies, the evergreen ground cover was blooming. Higher up, the hillsides were covered in bear grass, penstemon, and a riot of other alpine flowers and flowering shrubs.
A pack train passed us at Lost Horse Pass, headed up the Wahoo Pass trail. We soon followed, enjoying the prolific stands of bear grass, whose pungent blossoms all but covered up the "horse exhaust" fumes.
Leaving Lost Horse Pass, the Wahoo Pass trail climbs up the north face of the basin forming the headwaters of Lost Horse Creek.
The trail climbs around the north end of Upper Twin Lake, affording views of the Lost Horse Creek drainage to the south. It was a nearly cloudless day, but mild after a week of heavy thunderstorms and overnight temperatures dipping into the 50s in the lower valleys.
A pleasant surprise awaits as tiny Mud Lake, unnamed on some maps, comes into view as we climb through 7200 feet. Mud Lake sits in a hanging valley several hundred feet above Upper Twin Lake.
The trail starts a long double switchback to climb the face of the basin to Wahoo Pass.
Beyond Wahoo Pass, the trail skirts the edge of a meadow at the base of the rocky Bitterroot divide that separates Idaho and Montana, then begins a steep switchback trail leading into Idaho's Selway-Bitterroot Wilderness to the west.
Turning back eastward, retracing our steps gives excellent views of Mud Lake and Upper Twin Lake far below.
As the trail traverses the north side of the basin, an old, unmaintained trail leads to the outlet end of Mud Lake. Rivulets of cold mountain water trickle from the steep hillsides to feed the lake. All the shallow high mountain lakes sport car-sized boulders pushed from the surrounding cliffs to the middle of the lake by aeons of snow and ice.
A steep descent on the old trail detours around erosion gullies and fallen trees to arrive back at Upper Twin Lake near the outfall from Mud Lake. In mid-summer, the water is still crystal-clear, and the seepage from the steep basin sides floods the trail near the lake. The old trail follows the west shore back to the parking lot and campground at the head of Lower Twin Lake. A most pleasant Sunday mid-day outing. The hike took about three hours of sight-seeing and wildflower-spotting. These jewel-like mountain lakes in a basin filled with wildflowers and alpine varieties of spruce, pine, and fir are well worth the 20 miles of one-lane rock-strewn primitive road winding down the canyon. The road is posted "not maintained for cars and trailers," and rightly so, with steep grades, dips and humps over boulders, many blind turns, and loose rocks the size of footballs in the road.