Boeuf Tensas Basin of Arkansas Potential Natural Vegetation

The mapped area is located in southeastern Arkansas where it is bounded on the north and east by the mainstem levee systems along the Arkansas and Mississippi Rivers, and on the west by uplands.   The basin continues into Louisiana to the south, but the coverage of this map extends only to the state line, incorporating approximately 1.24 million acres.  Separate maps cover the Louisiana portion of the basin as well as the Macon Ridge upland and Ouachita River lowland. 

There are two separate lowland areas partly separated by the northern end of Macon Ridge that are collectively referred to as the Boeuf-Tensas Basin.  The Boeuf Basin is a narrow lowland on the west that consists of sediments deposited in past meander belts of the Arkansas River. It is named after the Boeuf River, but in Arkansas that stream flows entirely within the Macon Ridge uplands to the east before entering the lowlands in Louisiana.  In Arkansas, the principal stream is Bayou Bartholomew, which flows within an abandoned course of the Arkansas River.  To the east of Macon Ridge is the Tensas Basin, which is a very narrow area extending from the mouth of the Arkansas River into Louisiana, where it widens considerably.  In Arkansas it consists primarily of backswamp deposits of the Mississippi River.  Macon Ridge itself is a remnant of the glacial outwash that was deeply deposited throughout the Mississippi Alluvial Valley during periods of waning continental glaciation.  For the purposes of this map, the Boeuf-Tensas Basin is considered to include both of the two major lowland areas as well as the intervening portion of Macon Ridge and some parts of the adjacent modern meander belt of the Mississippi River where those areas lie west of the mainstem levee system.

Surface water entering the Boeuf-Tensas Basin arrives as precipitation or as runoff from the hills along the western flank of the basin. All drainage is to the south, leaving the Arkansas portion of the basin via Bayou Bartholomew, Bayou Macon, or the Boeuf River. Prior to construction of modern levees, major Mississippi and Arkansas River floods would have inundated most or all of the area, and poor internal drainage produced wet conditions over large areas even without flooding.  Much of the natural drainage system has been deepened and straightened and ditches have been added to further improve drainage.