This report provides a comprehensive assessment of the state of natural resources at Big South Fork National River and Recreation Area (BISO). It also addresses sets of stressors that threaten these resources and the biological integrity of habitats in the park. This assessment focuses on vital signs outlined by the Appalachian Highlands Inventory and Monitoring (I&M) Network (APHN), as well as on attributes relevant to the park's natural resources. Assessed attributes are roughly organized into broad groups of resources as follows: air quality, atmospheric deposition, weather and climate, water quality, vegetation, animal communities, and landscape dynamics.