Old growth forest, you'll only hear the river and an occasional train on the other side. Trail has tech climbs on the canyon walls and some rock gardens. Hardly known, beautiful, cool, shady. Best trail I found in Montana.
From I-90 northwest of Missoula exit at highway #135 at St. Regis and before reaching Paradise parking lot and trail head on the west side of the highway by the 14 Mile Bridge. Trail is 9 miles each way. Trail starts under train tressel.
http://www.singletracks.com/item.php?c=1&i=3165