Louisiana's Atchafalaya Basin is a resource-rich ecosystem in the southeastern U.S. that has come to symbolize the life of Louisiana, serving as a place of livelihood, home, and a significant part of the state's culture and history while also functioning nationally as a crucial drainage conduit that provides flood relief for rivers draining 2/3 of the continental U.S. and as the nation's largest repository of freshwater forests. The federally authorized Atchafalaya Basin Floodway System, Louisiana Project, encompasses 595,000 acres bounded by the Missouri-Pacific Railroad tracks just south of U.S. Highway 190, Morgan City on the south, and floodway protection levees on the east and west. In 1996 the Louisiana Department of Natural Resources was named the lead state agency to develop a plan to protect and develop the Basin with the U.S. Army Corps of Engineers as directed by Congress, and the Louisiana Legislature created the Atchafalaya Basin Program and its advisory Research and Promotion Board in 1998, completed the State Master Plan that year, approved it unanimously in 1999, and empowered the program through Act 3 and Act 920 of the 1999 Louisiana Legislature to implement and manage the comprehensive state master plan. The Old River Control Structures and Navigation Locks near Simmesport provide access between the Mississippi and Red Rivers and the Basin and are designed to pass up to one-half of the flow of the rivers during a major flood, while the floodway managed by the U.S. Army Corps of Engineers forms the physical core of the area addressed by the Atchafalaya Basin Program. In Avoyelles Parish, thousands of years of silt from ancient paths of the Mississippi River created swampland with hundreds of miles of swamps, bayous, and oxbow lakes that gave rise to numerous state and federal wildlife refuges; the parish is home to descendants of original French Creole families and several Native American tribes drawn by flood-safe prairie, contains abundant wildlife, and has been governed by a police jury since its creation by legislative act in 1808, with 11 wards, nine incorporated towns, and an Indian Reservation today.