The Flint Henderson Watershed covers an area of 1,966 square miles and is located in southern Oklahoma. The hydrology of the watershed is characterized by a humid subtropical climate with hot summers and mild winters. The watershed experiences high precipitation levels averaging about 44 inches annually, and snowfall is uncommon. The surface water in the area is mainly supplied by the Red River, which is the largest river in the watershed. The reservoirs in the watershed are known for their recreational activities, such as fishing and boating. The primary water constituents in the reservoirs are dissolved oxygen, nutrients, and sediment. The climatic trend in the watershed has been toward increased precipitation in recent years, which has led to flooding and erosion. The Flint Henderson Watershed supports a diverse range of wildlife, including fish, birds, and aquatic plants.