Arkansas County is located in the Arkansas Delta (in Arkansas, usually referred to as "the Delta") a subregion of the
Mississippi Alluvial Plain, which is a flat area consisting of rich, fertile sediment deposits from the
Mississippi River between
Louisiana and
Illinois. Within the Delta, Arkansas County is almost entirely within the
Grand Prairie subregion, historically a flat grassland plain underlain by an impermeable clay layer (the Stuttgart soil series). Prior to the 19th century, flatter areas with slowly to very slowly permeable soils (often containing
fragipans) supported Arkansas's largest prairie, covered in prairie grasses and forbs, with oaks covering the low hills and ridges, and pockets of floodplains with bottomland hardwood forests. This region was a sharp contrast to the bottomland forests that once dominated other parts of the
Mississippi Alluvial Plain. Cropland has now largely replaced the native vegetation. Distinctively, rice is the main crop; soybeans, cotton, corn, and wheat are also grown. The rice fields provide habitat and forage for large numbers and many species of waterfowl; duck and goose hunting occurs at this important spot along the
Mississippi Flyway. Two different eco-regions border the Grand Prairie along the major rivers forming the county's east and southern boundaries: the Arkansas River Holocene Meander Belt and the Western Lowlands Holocene Meanders. These areas of flat floodplain contain the meander belts of the present and past watercourses, point bars, natural
levees,
swales, and abandoned river channels. Some of the most extensive remaining tracts of native
bottomland hardwood forest in the Mississippi Alluvial Plain remain along these rivers. Along the banks of the White River in Arkansas County, these forests are preserved in the
White River National Wildlife Refuge. According to the
U.S. Census Bureau, the county has a total area of , of which is land and (4.4%) is water.
Hydrology trees along the shores of Lower White Lake Water is an extremely important part of Arkansas County's geography, history, economy, and culture. The many rivers, streams, and ditches crossing the county have featured prominently since prehistoric times, and many of the hundreds of archaeological sites, including the
Menard–Hodges site, are along waterways. The navigability of the Arkansas River has been important for every civilization in Arkansas County since prehistory. Tribes of
Quapaw,
Casqui, and
Mississippian cultures were settled in the area along the rivers. Three major rivers form much of the county's boundaries: Arkansas River,
Bayou Meto, and the
White River. Within the county,
La Grue Bayou is an important watercourse. Rivers brought early prosperity to the county during white settlement for navigation. The county saw battles for control of the rivers during the
American Revolution in 1783 at
Arkansas Post, and the
Civil War in 1862 and 1863 at
Saint Charles and
Fort Hindman, respectively.
Protected areas Several agencies own and maintain areas of natural and cultural value for enjoyment and use by residents and visitors of Arkansas County. Along the county's eastern boundary, of the
Dale Bumpers White River National Wildlife Refuge protect
Mississippi lowland forests along the White River. In the western part of the county, of the George H. Dunklin Jr. Bayou Meto Wildlife Management Area is managed by the
Arkansas Game and Fish Commission to preserve natural woodlands and wetlands for wintering waterfowl within the Mississippi Flyway. At the southern tip of the county, the
bottomland hardwood forest area between the Arkansas and White is preserved in the Trusten Holder WMA. The area is well known for hunting and fishing, and
bald eagle watching in winter. The AGFC also maintains the Ethel WMA, a area known for small game hunting, formerly open only to residents of
Ethel. , marking original locations of homes, blacksmith shops, and Arkansas's first territorial capitol. The Arkansas Natural Heritage Commission maintains two small sites in Arkansas County: the Roth Prairie Natural Area and the Striplin Woods Natural Area. Roth Prairie is a flat plot south of Stuttgart, one of the few remaining
tallgrass prairies typical of the Grand Prairie prior to leveling and clearing for human settlement. Striplin Woods preserves a very biodiverse section of old growth bottomland hardwood forest along the White River located within the White River NWR, and is comanaged with the
U.S. Fish and Wildlife Service. Along the Arkansas, the
U.S. Army Corps of Engineers maintains a total of 160 campgrounds at Merrisach, Notrebes Bend, Pendleton Bend, and Wilbur D. Mills Use Areas, each with electric hookups, boat ramps, and restroom facilities. The Corps also maintains the Moore Bayou Day Use Area on the Arkansas, providing access to the Arkansas Post Water Trail, and Wild Goose Bayou Day Use Area on the Arkansas Canal. The primary cultural site in Arkansas County is
Arkansas Post, the historic
entrepot near the confluence of the Arkansas and Mississippi Rivers, and early epicenter of European settlement in the region. Founded in 1686, Arkansas Post was established at various sites near the confluence, often moving after flood events. Though remains of the post have been lost by movements of the Arkansas River, a small townsite is preserved as the Arkansas Post National Memorial. The nearby
Arkansas Post State Park preserves the history of early settlement on the Grand Prairie through a five-building museum. The central structure is the 1877 Refeld-Hinman
dogtrot house. ==Demographics==