In 2009 the US Department of Energy began a project for establishing an on-line information system for geothermal resources in the United States, its territories, and the surrounding seas. The National Geothermal Data System (NGDS) came on line in 2013 and is now accessible by the public, although it is still receiving data from the state geological surveys, universities, and private entities participating in the project. As part of establishing NGDS, a team based at Texas Tech University examined wire-line logs from 8000+ wells in the US Exclusive Economic Zone of the Gulf of Mexico, and tabulated bottom-hole temperatures (BHTs) into a database accessible by geographic information system (GIS) software. BHTs from ~1700 of the wells have been corrected for the thermal disturbance associated with drill fluid circulation. The volume of the corrected BHT database is three times greater than the one previously available to the public. The corrected BHTs have been spatially interpolated into GIS maps of geothermal gradients and sedimentary temperature distribution of the northern Gulf of Mexico shelf. There, geothermal gradients show a general trend of high values (> 0.04°C/m) off Texas, especially along the Corsair fault zone, low values (0.015 to 0.02°C/m) off Louisiana, and intermediate values (0.025 to 0.03°C/m) off Alabama. We hypothesize that the low gradients off Louisiana are primarily due to the thermal effect of high sedimentation rates off the Mississippi Delta. In order to test the hypothesis, we are generating one-dimensional basin models that incorporates the geothermal gradient data, thermal conductivity measurements made on core samples, and sedimentation history inferred from well logs and seismic data.