Important Rivers# A Arkansas River B Brazos River C Canadian River Cimarron River Colorado River Colorado River of Texas Columbia River Cumberland River D Des Moines River G Gila River Green River J James River K Kuskokwim River L Little Missouri River M Milk River Mississippi River Missouri River N Niobrara River North Platte River O Ohio River Ouachita River P Pecos River R Red River Red River of the North Rio Grande S Sabine River Saint Lawrence River Sheyenne River Smoky Hill River Snake River T Tanana River Tennessee River Trinity River W Wabash River White River (Arkansas) White River (Missouri River) Y Yellowstone River Yukon River