Rivers were an essential part of the expedition. The flow of a river creates massive energy. The story of hydropower in America is the story of taking this massive natural force of energy and harnessing it to create electrical power for millions of people. Join us from Garrison Dam in North Dakota and learn how dams are built, how their technology creates electricity, and how that electricity gets from the dam to the light switch in your home. Join experts from the United States Army Corps of Engineers as we investigate these scientific questions. From the Series:Lewis and Clark Then and Now