Sunset Falls on the East Fork Lewis River has a Day Use Area ($5 day use fee) and Campground.  The trail from the Day Use Area parking lot to the falls is short, but you can easily extend a hike by walking the Forest Service roads and exploring side trails.  When I was there, I followed NF-42 about 1-1/2 miles along the river and explored several short side trails from the road to the river.