Southwest of Missoula and west of Lolo Hot Springs, the Kelly Creek is a catch & release area known for its cutthroat trout. Many people liken Kelly Creek to the St Joe River to the north. Both are of similar size, and many fly fishermen hit both in the same week. The lower section (10 miles) is accessed by a parallel gravel road (Moose Creek Road). The upper section of the river is remote and does not get much traffic along Kelly Creek Trail. Try the upper sections until late July and then move downstream in late summer.
Overall, Kelly Creek is the 2nd most popular fly fishing river of all 17 fly fishing spots in Idaho.