This lake was the only natural lake in Texas until it was artificially dammed in the early 1900s, when oil was found and for flood control in 1914. A new dam replaced the old one in 1971. Caddo Indian legend attributes the formation of the lake to a giant flood. Scientists believe the lake formed when floodwater, blocked by massive log jams on the Red River, backed up into the Cypress Bayou watershed.
In the late 18th or early 19th century, Caddo Indians settled on this rich land, where according to tribal legend, “water thrown up into the drift along the shore by a wind” formed Tso'to (Sodo) Lake. Legends tell of the formation of the lake and Sha'childi'ni (Timber Hill), the first and last known Caddo village in this area. People have lived in this area for at least 12,000 years. For centuries, they hunted and gathered among the wetlands, forests and broad floodplains. Then they began to settle in permanent villages. The Caddo hunted wild game with bows and arrows, fished, and farmed corn, beans and squash. They built ceremonial centers and maintained far-reaching trade routes.
The park's original improvements were made by the Civilian Conservation Corps. They were begun by Company 889 in June to November of 1933 and completed by Company 857 between October 1934 and March 1937. The U.S. Army had 15 barracks and an Army mess hall that were converted into the nine log cabins and group recreation hall that we use today. There is also a CCC pavilion and remnants of original picnic sites and a latrine along the trails.