After Lewis and Clark ended their journey westward in 1806, an expedition known as the Corps of Discovery, the Missouri River would prove to be a vital link between the east and west. Flowing right through the heartland, the Missouri River is the longest river in the U.S. and is an important economic resource to the region, the nation and the world. Before the Missouri River became the navigation hub it is today, it was an untamed, wild body of water prone to flooding, known for changing paths, with a floodplain as wide as a mile in some places. By the late 19th century, the government realized the value the river could have on westward expansion and began the process of taming the river.