Each feature within this dataset is the authoritative representation of the boundary of each U.S. Department of Energy Office of Legacy Management (LM) site listed as a current in the Site Management Guide (https://www.energy.gov/lm/downloads/site-management-guide). The dataset includes boundaries from Puerto Rico to Alaska and is only applicable to the extents contained within the dataset. All features are maintained as derived boundaries that were created by combining all component extents defined by a legal description for Category 1, 2, and 3 sites or a historic report for Category 1 sites as defined in the Site Management Guide. A general description of the components is included in the feature attributes. The dataset was designed to align with the NGDA Real Property Theme (https://www.fgdc.gov/initiatives/ngda-management-plan).