Hello!
I am trying to make my own custom basemap of the DC, Maryland, Virginia, and West Virginia area, as we need to use specific symbology on the basemap itself. Unfortunately, as I search around, all the layers I find are political or administrative boundaries, meaning they are not great representations of the actual physical land. The best I have found is the Maryland Detailed Boundaries - County Boundaries layer :
This works great, as it shows the actual shape of the land, however that still leaves me with nothing for DC, VA, and WV.
Are there any sources people know about? I have tried VA and DC's GIS data portals, but haven't gotten any good layer. Please let me know!
Could you use the Vector Tile Style Editor to modify the symbology of an existing basemap?
If you are looking specifically for watershed/drainage data, the USGS has watershed polygons and flowlines for the United States. Here's an article I found on how to access this layer: https://www.usgs.gov/faqs/where-can-i-get-watershed-maps - likely also in Living Atlas.
At this point I would call or email the state offices to ask. I'm willing to bet they have something. It just might not be on their portals.