This document summarizes the archiving efforts of the 2010 Deepwater Horizon oil spill by the California Digital Library. It captured over 500 sites totaling over 76 million documents and 2 terabytes of data in the initial response tapering to 200 sites per month. Key challenges included site selection, management of the large number of captures, and quality assurance of the archives. Collaboration with subject experts and utilizing existing tagging workflows helped address these challenges at massive scale.