The Eastern Brook Trout Joint Venture (EBTJV) is a partnership between state and federal agencies, nongovernmental conservation organizations, and academia. The EBTJV is focused on an effort to protect, restore, and enhance brook trout populations throughout the historic range of the Eastern brook trout. One of the goals of the EBTJV was to produce a subwatershed dataset indicating the current distribution of brook trout populations and their perturbations. This data will aid in quantifying problems, identifying information gaps, and setting restoration priorities. The subwatershed classifications are based on a combination of quantitative information collected by state agencies and qualitative judgment calls by local experts.