JENNINGS LAKE. Jennings Lake is six miles northwest of Marietta in northwestern Cass County (at 33°15' N, 94°36' W). The mile-long narrow lake, formed by a channel of the Sulphur River, lies wholly within a clayey alluvial area that is subject to inundation from the Wright Patman Dam during periods of heavy rainfall. Vegetation native to the area includes water-tolerant hardwoods and conifers. The lake was named for Gilley Jennings, an early settler in the area.