The Lehigh Gorge Scenic Railway runs excursion trains from Jim Thorpe along the river and into the gorge. It is touristy in the best straightforward sense: sit by the window, watch the cliffs and trees slide past, and let the town's rail history do some work.
Autumn foliage trips are the famous ones and can sell out. Outside peak weekends, the ride is calmer and gives a good overview of the valley before walking or biking part of it.