The bad news: after about 1 hour we realized there was a Delaware Co. police vehicle parked behind our van. Needless to say, we were out of there way too soon, but there long enough to get some nice shots of the falls.
On a side note, this was the top terrace of a two-fall system. The second terrace was much larger, at least 4x as wide, and over 100' vertical drop. However, the lower falls were not accessible from out position.