I generally think that place names are for places, not for people. But I do think it makes sense that natural landmarks would seem more acceptable as names in their own area than cities.
I live 30 miles from the nation's capital, and you just don't hear of many kids named Washington here! It would be SUPER weird. Baltimore would be weird too.
However, I do know of a few Maryland kids IRL with place names representative of area geography:
Bay -- after the Chesapeake Bay
Tilghman -- after Tilghman Island, could also be Tilman, Tillman, or Tillmann
Harper -- Harper's Ferry, WV