The Red River is a tributary of the Mississippi River. It begins in Texas, and flows through the states of Oklahoma, Arkansas, and Louisiana. It merges with the Mississippi River in Louisiana. The river's name comes from the red clay that is found along it. The Red is about long. The biggest dam on the Red River is Denison Dam, which was created in 1943. It forms Lake Texoma. This lake covers 89,000 acres (360 square kilometers). There are also some other dams on the river's tributaries. At its end at the Mississippi River, it has a flow of 7,000 cubic feet (200 cubic meters) of water every second. In early 2009, the river experienced a series of catastrophic floods.