Final answer:
Oklahoma's two main river systems are the Arkansas River and the Red River, which serve as vital water resources for the state.
Step-by-step explanation:
Oklahoma is drained by two major river systems, which are the Arkansas River and the Red River. These rivers play a critical role in providing water resources for various uses including agriculture, urban consumption, and maintaining the ecological balance of the region. The Arkansas River flows southeast across the state into Arkansas, while the Red River forms part of the southern boundary of Oklahoma, separating it from Texas before continuing on to Arkansas and Louisiana.