The Kansas River (which is also called the Kaw) begins at the confluence of the Republican and Smoky Hill Rivers near Junction City and flows 171 miles to Kansas City, where it joins the Missouri River. The Kaw drains almost the entire northern half of Kansas, as well as part of Nebraska and Colorado (53,000 square miles in all), and is the longest prairie based river in the world. Come explore the Kaw with us in the River Atlas and on the River Inventory, and join us for float trips and other fun events on the river.