
Mount Airy and Ridgeville serve as northern anchor points for this 1940s landscape where the borders of Frederick, Carroll, Howard, and Montgomery counties converge. The Baltimore and Ohio RR cuts through the northern section, passing by Parrsville and the industrial-sounding Plane No 4. This area represents a critical watershed divide, where the headwaters of the Patapsco River and Patuxent River begin their descent toward the Chesapeake, separated by the high ground of the Parrs Ridge.
33 named features on this map. Tap any name to fly to it.
Don’t see what you’re looking for? This feature index may not catch every label — zoom into the map to look around manually.
5 editions found
1893 · Frederick
USGS Topo · 1:125,000
1894 · Frederick
USGS Topo · 1:125,000
1908 · Rockville
USGS Topo · 1:62,500
1908 · Seneca
USGS Topo · 1:62,500
1908 · Ijamsville
USGS Topo · 1:62,500
1909 · Mount Airy
USGS Topo · 1:62,500
1909 · Ijamsville
USGS Topo · 1:62,500
1923 · Rockville
USGS Topo · 1:62,500
1942 · Frederick
USGS Topo · 1:62,500
1944 · Walkersville
USGS Topo · 1:31,680