South Arkansas lies within the southernmost portions of Arkansas Gulf Coastal Plain and Delta regions. It encompasses the lower 15 counties of the state. In the 1920s, nationwide attention focused on South Arkansas when the Smackover Field was ranked first among the nation's oil fields. For five months in 1925, the 40-square-mile Smackover Field was th…South Arkansas lies within the southernmost portions of Arkansas Gulf Coastal Plain and Delta regions. It encompasses the lower 15 counties of the state. In the 1920s, nationwide attention focused on South Arkansas when the Smackover Field was ranked first among the nation's oil fields. For five months in 1925, the 40-square-mile Smackover Field was the focal point of one of the wildest mineral booms in North America. Today, south Arkansas's oil fields produce petroleum throughout a 10-county area.