Thomas Stone National Historic Site is just west of La Plata. US 301 runs through this town on the eastern side of the Potomac. MD 6 crosses US 301 in La Plata. When we visited, we turned left onto MD 6 from US 301 as we were coming north out of Virginia. Near Port Tobacco, there is Rose Hill Rd. which we turned right on. Can you add a waypoint for that road? On the way out, we continued north along Rose Hill Rd. which intersects with MD 225 and then is Marshall Corner Rd. on the other side. There is a corresponding waypoint on MD 225 called MarCorRd. I know that Rose Hill Rd. is just a county road, but this extra waypoint will accurately show our path in and out of the site.
Here is the GSV of the sign for the turn onto Rose Hill Rd with the park sign.
https://www.google.com/maps/@38.5152588,-77.0183884,3a,75y,259.7h,82.41t/data=!3m6!1e1!3m4!1sBGQKI7IRJP-ZdZZtb20QfQ!2e0!7i3328!8i1664Mike
