For reference, here's a map of the area from west of
Mt. Airy to Monrovia, Maryland.
This map represents data from Harwood (1979), USGS maps (1945
and 1980), and aerial photos (1980) combined with research from
my hiking and photographing the area many times over the course
of several years.
The alignments are depicted on the map by colors that indicate
the date of opening. The same colors are overlaid on some of
the photos below to assist visualizing the route.
Even though this map is called "Western Approach", this tour page
continues the east to west progress of the tour's preceding pages.