The marine Eocene-Oligocene transition of 49--34 million years ago was a critical turning point in Earth's climatic history, when the warm, high-diversity "greenhouse" world of the early Eocene ceded to the glacial, "icehouse" conditions of the early Oligocene. This book surveys the advances in stratigraphic and paleontological research and isotopic analysis made since 1989 in regard to marine deposits on the coasts of North America. In particular, the book summarizes the high-resolution details of the so-called "doubthouse" interval, which is critical to testing climatic and evolutionary hypotheses about the Eocene deterioration.