U.S. Fish & Wildlife ServiceDitches were mapped within a subset of the Priority Saltmarsh Sparrow patches identified by the Atlantic Coast Joint Venture (2022; available at https://acjv.org/saltmarsh-sparrow/restoration-priorities/ ) which are based on the National Wetland Inventory Estuarine Emergent Wetland (E2EM) delineation. A total of 17 patches were comprehensively mapped for major/primary ditches and 1 patch [Barnstable Marsh, MA] was partially mapped for major/primary ditches. The mapping procedure followed two main steps: 1) obtain historical and current imagery and topographic maps of priority marshes for restoration identified by the Atlantic Coast Joint Venture to benefit the Saltmarsh Sparrow, and 2) digitize the locations of ditches in these marshes based on visible signatures. Each marsh had at least 10 years of historical aerial imagery available and the oldest year of clear/quality imagery ranged from 1931 to 1985. When identifying ditches, we always referred to the oldest year of clear/quality imagery in conjunction with recent imagery. We only digitized ditches for which we could see a visible signature in at least one year of aerial imagery; we did not infer the location of a ditch without a visible indication of its presence. For example, if a ditch appeared to end in the middle of a marsh, we mapped it as such and did not assume it continued to the marsh edge or nearest water feature. Aerial imagery (of any year) was used as the primary source of information when identifying ditches. Topographic maps were used as supporting information in specific cases: 1) If we were uncertain of the full original extent of a ditch due to low image resolution or other factors, 2) If we observed an unusual interruption in the "normal" grid pattern of ditches, or 3) If we observed an area of unusually low ditch density. A Standard Operating Procedure (SOP) containing the full methodology can be accessed at: https://ecos.fws.gov/ServCat/Reference/Profile/150234ArcGIS FeatureLayerhttps://hub.arcgis.com/datasets/bcecfbb0a1e2495180f11d5af45960d9_0engU.S. Fish and Wildlife Service Open DataPublicFWS ACJV NE marsh digitized ditches 2022 [United States]Web servicesUnited States2022