12-digit hydrologic unit outlet (pour) points for the NHDPlus V2.1 WBD snapshot

This USGS data release consists of three datasets representing three derived outlets or "pour points" for each 12-digit hydrologic unit (HU12) in the Watershed Boundary Dataset (WBD) snapshot delivered with NHDPlus V2.1. The three related pour point locations, each delivered in a stand-alone dataset, are: "from" (fpp) and "to" (tpp) points that identify the location where flow leaves the HU12 polygon based on a flow direction raster, and a third "vector pour point" (vpp) selected "upstream" used to identify flow confluences near the "from" and "to" pour point locations. The points are derived from the NHDPlus V2.1 flow direction rasters and the WBD snapshot delivered with NHDPlus V2.1.