Which river is known for having been explored by Lewis and Clark?

The Missouri River is known for having been explored by Lewis and Clark during their famous expedition from 1804 to 1806. This journey was undertaken to explore the newly acquired Louisiana Territory and to find a route to the Pacific Ocean. The Missouri River served as a primary navigational route for the expedition as they traveled westward from the confluence of the Ohio River and up through what is now the central United States.

The exploration of the Missouri River was vital for mapping the region and for understanding the various indigenous peoples and natural resources that lay in the area. Their detailed documentation along this river helped provide valuable information for future American expansion and settlement.

The other rivers mentioned, while notable, were not the primary focus of Lewis and Clark's exploration. The Colorado River is in the southwestern U.S. and was explored later. The Columbia River was explored during voyages around the same time but not by Lewis and Clark specifically. The Red River, which flows along the border of Texas and Louisiana, also did not play a role in their expedition.