Abstract In 1985, Compagnie Generale de Geophysique (CGG) acquired 300 mi (483 km) of regional, nonexclusive Vibroseis seismic data in the Rough Creek graben area of western Kentucky and southern Illinois. Data consist of four dip lines and a 100 mi (161 km) strike line (Figure 15-1). Field acquisition, processing, and display parameters for the data are presented in Table 15-1. Energy penetration was good and "seismic-basement" reflections were observed locally down to two-way travel times of approximately 3.0 seconds. Sonic logs and formation tops from two deep wells in Webster County, Kentucky (Table 15-2), were integrated into the study. Depth-to-time conversion functions were generated for each well, and a two-way time representation of the wells was prepared. Major seismic events were identified by correlating formation tops in the wells to seismic data. The major seismic reflections were then traced around the seismic grid. The nature of the grid did not allow us to "tie loops"; "jump" correlations were, therefore, commonly made across faults. Such correlations were based primarily on reflection character and stratigraphic thickness. Interpretation was relatively straightforward for shallow data within the Moorman syncline, but correlations across the northern and southern boundary faults of the Rough Creek graben and in the deeper section are more tentative. Two-way time and isochron values were read from the seismic data and then converted to depth and thickness respectively, using interval velocities derived from well data.