For each of the four Miocene sequences, polygons representing producing areas within fields were created by constructing a grid of ¼ sq. mi. cells and proximal polygons centered on all producing wells and then combining and merging the adjacent polygons having the same value for field name. Although the polygons are based on the producing wells only, they may also include some dry holes. The producing intervals were determined by comparing the depth of production to the structure contours (see metadata for the structure contours). The data are provided in four shapefiles--one for each Miocene sequence (Lower 1, Lower 2, Middle and Upper). These datasets contain basic data and interpretations developed and compiled by the U.S. Geological Survey's Framework Studies and Assessment of the Gulf Coast Project. Other major sources of data include publicly available information from state agencies as well as publications of the U.S. Geological Survey and other scientific organizations. In cases where company proprietary data were used to produce various derivatives such as contour surfaces, the source is cited but the data are not displayed.