Oklahoma is defined by significant river systems and massive reservoirs.
* **Major Rivers**: The Arkansas River, the Red River (which forms the southern border with Texas), and the Canadian River. * **Major Lakes**: Lake Eufaula (the largest by volume in the state), Lake Texoma (a massive reservoir shared with Texas, famous for striped bass fishing), and Grand Lake o' the Cherokees (a major resort and boating destination). * **Illinois River**: A designated scenic river in the northeast, wildly popular for summer float trips in canoes and kayaks.