This volume is a collection of papers that resulted from a symposium on Recent and Ancient Nonmarine Depositional Environments which was held in Casper, Wyoming on June 3 to 7, 1979. The nineteen papers may be divided into: (1) a review of recent and ancient nonmarine modes, (2) alluvial fan and fluvial deposits, (3) lacustrine deposits, (4) eolian deposits. Knowledge of the physical, biological and chemical characteristics and depostional environments on nonmarine sedimentary deposits has increased significantly over the last decade. Correspondingly, there has also been an increase in our ability to apply this knowledge to the exploration and exploitation of contained energy resources and minerals.