Which watershed
are you in?

Type any U.S. address. This draws the watershed it sits in (the USGS Hydrologic Unit Code (HUC) boundary) on the map, from sub-basin down to local subwatershed.

Heads-up: unlike the Instagram tool, this one isn't offline. Your address goes to OpenStreetMap (to geocode it) and the USGS National Map (to fetch the watershed). Both are public services; nothing is stored.