The Bitterroot Valley  narrows upstream from Hamilton , and the character of the countryside changes as it passes Darby, Lake Como, and Sula. The river flows faster here, and the mountains encroach. With rocky ramparts closing in, the Bitterroot ceases to be a broad valley dotted with farms and subdivisions and becomes a wooded canyon.
People scramble for logging jobs or work for the Forest Service or at the local Job Corps center. For the traveler, recreation is the draw in the upper Bitterroot.
Darby marks the southern edge of old Lake Missoula, which existed in the bad old days when the entire Missoula Valley system was alternately underwater and drained as the ice age saw necessary.
At Connor, just south of Darby, the Bitterroot River divides into the West Fork and the East Fork. The highway also divides. Highway 93 follows the East Fork up Lost Trail Pass over the Continental Divide south into Idaho or east into the Big Hole Valley . The West Fork proceeds up Highway 473 into deep canyons, first along a paved road, then along an improved road to Painted Rocks Lake.
At Sula on Highway 93, the East Fork opens onto pastureland. All of a sudden it’s cattle country, a last reprise of the Bitterroot Valley before it disappears into the heights of the Continental Divide.