Over 300 km of Dow Company seismic reflection data have been interpreted in western Tennessee and eastern Arkansas. The data overlie the southeastern margin of the Reelfoot Rift. This rift margin truncates seismicity of the northwest-striking Reelfoot thrust fault and recent research suggests that the rift margin may be accumulating strain. Thus, a better understanding of the rift margin’s structure is important in assessing its seismic potential. The reflection lines reveal zones where the reflectors are disrupted and also distinct faults. Some of the faults extend through the Paleozoic, Cretaceous, and into the Tertiary Mississippi embayment section. The faults trend approximately N30E and are parallel to the southeastern rift margin as previously defined by gravity and magnetics.