This ArcGIS Map Package contains information on brook trout occupancy in the southern portion of the brook trout range (PA and south). Fish sample data from a number of state and federal agencies/organizations were used to define patches for brook trout as groups of occupied contiguous catchment polygons from the National Hydrography Dataset Plus Version 1 (NHDPlusV1) catchment GIS layer. After defining patches, NHDPlusV1 catchments were assigned occupancy codes. Then state and federal agencies reviewed patches and codes to verify data accuracy. A similar effort is currently being conducted by the Eastern Brook Trout Joint Venture to develop occupancy data for the remainder of the brook trout range including states of New York, Maine, New Hampshire, Connecticut, Vermont, Massachusetts, Rhode Island, and Ohio. This ArcGIS Map Package contains data for the entire southern portion of the brook trout range with preset symbology that displays brook trout occupancy. The Map Package also includes the same information clipped into seperate layers for each state. State information is provided for the convenience of users that are interested in data for only a particular state. Additional layers displaying state boundaries, quadrangle maps, and the brook trout range are also included as spatial references.