This polygon shapefile depicts geologic units as areas, such as lithologic contact, fault contact, and watershed boundaries for the Jackson Demonstration State Forest (JDSF), which is predominantly located on the coastal side of the Mendocino Range, the western-most range of the northern California Coast Ranges Geomorphic Province. The majority of the JDSF is mountainous, with elevations ranging from near sea level in the western portion of the JDSF to approximately 2175 feet in the eastern portion of the JDSF. The Coastal Terrane of the Coastal Belt of the Franciscan Complex forms the bedrock under most of JDSF. The geology and geologic history of JDSF directly influence the nature of the slopes and the types and rates of landslides present. The maps/data are useful in preparation of Timber Harvesting Plans, and for use by land managers for identifying areas of potentially unstable ground. The maps/data serve as a general guide to potential problem areas where more site-specific review is required. The scale of these maps limits the delineation of the various geologic and geomorphic features, and relative landslide potential categories. The information on these maps is not sufficient to serve as a substitute for geologic and geotechnical site investigations required under Chapters 7.5 and 7.8 of Division 2 of the California Public Resources Code.