In November 2010 the University of Texas Institute for Geophysics (UTIG) and Baylor University recorded a long-offset onshore/offshore seismic refraction line in the northern Gulf of Mexico (GoM) using 412 Texan recorders and geophones, 12 broadbands, and 43 short-period ocean bottom seismographs. The line is co-located with existing seismic reflection lines to obtain the best possible combined structural models of this rifted margin. Due to deeper penetration, the seismic refraction data will provide crustal thicknesses and much-needed constraints on the nature of the basement. Our main targets are therefore the boundaries of rifted continental crust, possibly exhumed continental mantle and volcanic crust across the margin of the Gulf of Mexico. The new data will subsequently help to improve plate reconstructions of the Gulf of Mexico and to better constrain the thermal history of this economically important basin.