This article describes an oil spill surveillance strategy implemented in response to BP's 2010 MC252 oil well blowout in the Gulf of Mexico. A three-pronged strategy consisted of Geographic Information System (GIS) monitoring of the surface slick, hydrodynamic modeling of the potential movement of the slick within the Basin, and weekly field reconnaissance. Our analysis was completed in near real time during the event and the results and predictions helped local responders minimize oiling impacts in Lake Pontchartrain. No prior planning was undertaken before this crisis response, and this article reports our support activities as they happened. For the GIS component, a remote sensing derived surface slick outline layer was obtained to produce near daily maps showing the slick's proximity to Lake Pontchartrain along with weather conditions and deployed response assets. This regular monitoring of the slicks' location was complemented by hydrodynamic numerical modeling that simulated the currents that determined the trajectories of oil particles. These data were ground-truthed through weekly reconnaissance trips that assessed the potential routes of oil penetration into Lake Pontchartrain for the presence of sheen, tarballs, and other oil constituents. Despite the ad hoc design and on-the-fly implementation, these three assessments provided consistent and actionable information.