Travel from the steamy delta beyond New Orleans, upstream to headwaters in great northern swamps, and along the Mississippi's greatest tributary, the Missouri. The crew encounter a wealth of wildlife, from tropical manatees to ancient horseshoe crabs, primitive giant fish, colorful herons, industrious beavers, deadly rattlesnakes, herds of buffalo, and prairie dog colonies. Dramatic reconstructions illustrate what the river was like when the first explorers encountered it, meeting Indian tribes and witnessing new wildlife spectacles.