Description: <A href="https://edg.epa.gov/metadata/catalog/search/resource/details.page?uuid=%7B53D0C152-12F3-4B1A-83A8-F0D7D98F3A8D%7D">Full Metadata</A> This EnviroAtlas dataset identifies relative ecosystem rarity using base landcover data from the USGS GAP Analysis Program (Version 2, 2011) combined with landscape ecology principles. This raster dataset is an index of relative rarity, from 0 to 100, with higher values representing greater rarity. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).