The April 20th 2010 explosion of the Deepwater Horizon offshore drilling rig led to the largest oil spill in U.S. waters. Federal government officials estimated that the deepwater well ultimately released over 200 million gallons of crude oil. Although decreasing amounts of oil were observed on the ocean surface following the well's containment on July 15th 2010, oil spill response officials and researchers have found oil in other places. This new book examines the fate of the oil from the Deepwater Horizon spill. Direct observation and measurement of the fate of the vast majority of the estimated 200 million gallons of oil presents a considerable challenge.