the nearby town of Hugo, impounds the river itself. Both are flood control reservoirs built and operated by the U.S. Army Corps of Engineers. Additional, smaller dams have impounded the waters of the tributaries over time, mostly for the purpose of powering sawmills and other light, localized industry. Notable geological features of the Kiamichi River valley include McKinley Rocks, the Potato Hills, Rock Town, and Lost Mountain. Tributaries Major tributaries of the Kiamichi River include Anderson Creek, Big Cedar Creek, Buck Creek, Buffalo Creek, Gates Creek, Jacks’ Fork Creek, Pine Creek, Tenmile Creek and Waterhole Creek. Watershed Drainage area The area of the river's watershed is . History Prehistoric era The Kiamichi River defined its region during prehistoric days. Its valley provided the only convenient means of traversing the region from north to south—much as now—and Native American peoples used it as a corridor. The Native Americans who lived in the region prior to European colonization of the Americas were generally Caddo, who were nomads. The powerful Caddoan Mississippian culture based at Spiro Mounds held sway over the Kiamichi River valley, which formed a part of its trade network. Archeological finds across the Kiamichi River basin attest to early life in its valley. A prehistoric fish weir, or trap, in the river in Pushmataha County, excavated by the Oklahoma Archeological Survey, is a particularly revealing site. Ancient Indians diverted the flow of the river with walls of stone to create a chute into which fish would flow. Radiocarbon dating of charred hickory and pecan hulls found at the site indicate a date of approximately 1,200 BC. Also found were stumps of cypress trees, a tree which has not grown in that portion of the county in perhaps hundreds of years. Over 220 archeological sites have been identified in Pushmataha County alone, indicating how widespread ancient and more recent settlement was in the region prior to European settlement. Of those sites, three date from at least 8,000 years ago; 145 date from between 2,000-8,000 years ago; and 22 date from between 500–1000 years ago. Modern era Discovery by Europeans occurred in 1719, when French explorer Bernard de la Harpe explored the Kiamichi River valley. French explorers were quickly followed by French fur trappers; they named most of Oklahoma's rivers. American explorers followed French ones, and were the first organized scientific surveys of the Kiamichi River. Thomas Nuttall traversed the Kiamichi and