Shallow-water carbonates of the Upper Jurassic Smackover Formation contain proven exploration targets throughout the U.S. Gulf Coast. Evaporites have played a role in Smackover reservoir development. Evaporites are found in the underlying Louann Salt, the overlying Buckner Formation, and within the Smackover itself. The Buckner has been important in three ways: 1) Buckner anhydrites and shales are important seals for Smackover reservoirs; commonly the Buckner inter-fingers with the reservoir at the updip limit of a field and as a result of basinward progradation, forms an impermeable cap; 2) during Buckner time early diagenesis of the uppermost Smackover occurred as brines were introduced into the lime sands of the Smackover from laterally adjacent tidal flats; and 3) thickness maps of the Buckner serve as a valuable exploration tool for the Smackover because porous facies are associated with Smackover highs underlying the Buckner thins. The stratigraphic relationship between the Smackover and Buckner is illustrated with conventional cores from a well in Columbia County, Arkansas.