Four Mile Creek State Campground is only 15-20 minutes from the US side of the falls. It's a relatively nice NY state campground, but you won't have full hook-ups. There's a KOA in Lewiston...about the same distance to the falls. It's a basic KOA...should be a little quieter than the KOA that's located on Grand Island, which would be another possibility, but it's right on the 190, so expect some traffic noise.