The Geologic Resources Inventory (GRI) is one of 12 inventories funded by the National Park Service (NPS) Inventory and Monitoring Program. The Geologic Resources Division of the NPS Natural Resource Stewardship and Science Directorate administers the GRI. This GRI report was written for resource managers to support science-informed decision making. It may also be useful for interpretation. The report was prepared using available geologic information. Chapters of the report discuss distinctive geologic features and processes, describe the geologic history leading to the present-
day landscape, highlight geologic issues facing resource managers, and provide information about the
associated GRI geologic map data. A poster (Plate 1, in pocket) illustrates these data.