Piegan Blackfeet
The Mandan and the South Piegan Blackfeet, among other Native Americans, knew of the falls. On June 13, 1805, Meriwether Lewis of the Lewis and Clark Expedition became the first white person to see the Great Falls (the largest of the five waterfalls). On the second day that the expedition camped near the series of falls, Meriwether Lewis discovered Black Eagle Falls.