The Lewis and Clark Expedition faced many obstacles and challenges on its journey west, and the Missouri River was among the mightiest. In 1804, the Corps of Discovery rowed and pulled with a heavy rope, called a cordelle, up the uncharted Missouri River through treacherous currents, with every mysterious bend and channel posing a challenge. Today the Missouri's flow has been tamed with dams, channels, and levees to reduce flooding and ease navigation, but even in modern times the river can return to its natural untamed ways. In 1993 and 1995, floodwaters rose to a level near the base of this sign. On May 24, 1804, Meriwether Lewis wrote of a very bad part of the river where the bank was falling in so fast that evident danger obliged the party to cross between the stable side and a sand bar in the middle of the river, and where the swiftness of the current wheeled the boat, broke the toe rope, nearly overset the boat, and sent all hands jumping out.