GEOCONNEX Knowledge Graph
The Geoconnex knowledge graph, an open community-contributed RDF graph linking U.S. hydrologic features via persistent identifiers. It integrates USGS reference features (NHDPlus High Resolution hydrologic units, Watershed Boundary Dataset subwatersheds, reference stream gages, and national aquifers) with community-contributed feature registries, and is served through the Geoconnex SPARQL and Triple Pattern Fragments endpoints.