This study is focused on determination of the significant reservoir rocks in the Siloam field, Clay County, in the Black Warrior Basin of northeastern Mississippi. The southwestern margin of the Black Warrior Basin has not been studied in great detail. The productive units of the Siloam field were identified as the Mississippian Rea and Carter sands. Thickness was determined using cross sections and isopach maps of Millerella, Carter, Sanders, and Abernathy sands. Isopach maps show thickness varied, which may indicate shifting deposition. Surface contour maps show that units dip consistently to the west or south. Thin sections and SEM images show very fine-grained sandstone, siltstone, shale, with common illite clay. Elemental maps show he field of view broken down by single elements and confirm the presence of quartz, clay minerals, pyrite, and calcite. The data generated by this study are significant Cbecause they can be used for reservoir modeling for Enhanced Oil Recovery (EOR).