Big Falls

Big Falls is the lowermost and tallest of the five waterfalls which make up the Great Falls of the Missouri River. The falls drop 87 feet and stretch a bit more than 600 feet wide, with the Ryan Dam situated immediately above the natural falls. The dam draws off the majority of the river for most of the year, greatly reducing the falls in volume - often to the point where just a trickle of water is flowing.
Some sources suggest that the Missouri River drops over 600 feet over the three mile run between Black Eagle Falls and Big Falls. Even taking into account the dam on top of Black Eagle Falls, the actual drop of the river to the bottom of Big Falls is just over 406 feet, and given that there are extensive stretches of flat water behind each of the dams, Great Falls should not be considered a collective series of waterfalls in the least.The waterfalls which make up Great Falls were discovered in 1805 by the Lewis and Clark expedition, and were immediately recognized as both a major impediment to travel further west using the Missouri River, as well as a major landmark.