Enipeus Vallis is located at the western edge of the Tempe Terra plateau in the Tempe-Mareotis region. The region lies on a broad topographic shelf bounded by the higher elevations of Alba Mons to the west and Tempe Terra to the east. The region slopes gently to the north with a gradient of 0.3° or less. The area is characterized by abundant lava flows, low volcanic shields, and small domes that are part of the Tempe Volcanic Province, a northeastern extension of the Tharsis Montes chain of volcanoes. Although spatially related to the large Tharsis volcanoes, volcanism in the Tempe Volcanic Province has a different eruptive style and has been likened to the basaltic plains volcanism seen in Idaho's Snake River Plain. This category of volcanic activity is intermediate between flood (plateau) basalts and Hawaiian volcanism.