This report is one of a series designed to characterize the hydrology of drainage basins within coal provinces, nationwide. Area 52 (in the Rocky Mountain Coal Province) includes the Green River Basin upstream from the Yampa River, and the Bear River upstream from the Bear Lake - a total of 23,870 sq mi. Area 52 contains over 3 billion tons of strippable coal, most of which is located in the arid and semiarid plains. The report represents a summary of results of the water resources investigations of the U.S. Geological Survey, carried out in cooperation with State and other Federal agencies. More than 40 individual topics are discussed in a brief text that is accompanied by maps, graphs, photographs, and other illustrations. Primary topics in the report are: general features, resources and economy, surface-water quantity and quality, and groundwater. (USGS)