From July 28 through December 20, 1975, the U.S. Geological Survey conducted a high-resolution geophysical survey on the Upper Continental Slope in the Gulf of Mexico north of Latitude 26°N. The survey was limited to water depths between 100 m and 1000 m with seismic lines spaced from 7.5 to 18.5 km apart in a reconnaissance grid pattern. The data were collected by Western Geophysical Company of America under an exclusive contract with the Geological Survey.