Yellowstone's Lower Falls is 308 ft. high and can be seen from various points on the South Rim Trail. The Lower Falls is often described as being more than twice the size of Niagara, although this only refers to its height and not the volume of water flowing over it. The volume of water flowing over the falls can vary from 63,500 gal/sec at peak runoff to 5,000 gal/sec in the fall.