the columnar basalt almost looks like tall trunks of trees the lines are so defined. You can see a little cave to the right of the falls at the bottom. "The North Umpqua River has carved a sinuous gorge out of the lava flow, resulting in a waterfall of 113 feet in height - a 28 foot upper tier which plunges into a pool flanked by a deep alcove, followed by an 85 foot plunge into a large pool."