There are four waterfalls on Oneonta Creek and the names have proven difficult to pin down. The lowest falls at the head of Oneonta Gorge, is often called Oneonta Falls, but in fact that is Lower Oneonta Falls. The next one, near the Trail #438 bridge is often called Upper Oneonta Falls, Oneonta Bridge Falls or as we have done, Middle Oneonta Falls.
Lower Oneonta Gorge is not accessible by trail. Rather you must walk up the creek bed, over a large and perhaps unstable log jam, through the gorge, and up to your waist (or even torso depending on your height and the time of year) in water until you finally see your prize.
Lower Oneonta Falls is worth the small challenge it takes to get in there, but I suggest you go on a summer weekday... the water is too cold during other seasons, and the gorge gets very busy on the weekends. You'll definitely want your solitude for this one!