The Lehigh river is truly a jewel of a river. With over a hundred miles of designated scenic river, many which pass through the edge of the Appalachia mountains. This tributary to the Delaware river has a multitude of species for the fly angler to enjoy. Fly fishing The Lehigh River for trout yeilds some very large fish, the average being 18 to 20 inches with many exceeding 21 inches. Warm water species like smallmouth bass and musky can be found in a few stretches.