The objective of the National Park Service (NPS) Vegetation Inventory is to classify vegetation as ecological community types in each of more than 250 NPS Inventory and Monitoring park units ("parks") in the United States outside of Alaska and to map vegetation to that classification scheme developed for the unit. This guidance is a revision and update of the 1994 guidance on vegetation classification within the NPS Vegetation Inventory (The Nature Conservancy and Environmental Systems Research Institute 1994) and supersedes the 1994 version.