Switchback v2.0

[NW Mailing List]

Bruce, et al

This is wandering off topic a bit...
Another problem with USGS topo quads in areas with narrow valleys and very steep terrain is in the location of cultural (man made) features.   The old standard for positional accuracy for “well defined points” ( like a road intersection) on 1:24,000 scale map was 40 feet.   In contrast, in a narrow defile that included a river or creek, road, power line, and railroad track, the cartographer might not place them in their correct location.  On the ground, both the road and track might be on the same side of a river.   But when the map separate for drainage was overlaid on the contour separate there was not space to put those cultural features on same side of the river because of the size of the symbology (road width) the road or railroad would be put on the other side.  I could not find a specific “order of precedence” in either the 1918 or 1928 editions of Topographic Instructions of the United States Geological Survey.   In the 1970s and 1980s empirical evidence indicates that railroads were located first, then roads, then power lines.   Interestingly in the 1918 edition, it does say that railroad switches will be shown as accurately as possible within the limits of other map features.  

Before the advent of the using aerial photography for map revision, it was still done by field survey crews doing ground measurements and taking detailed written field notes.  

Some of the “fuzziness” is related to how the paper maps were scanned and rendered.  Many of the lines (especially supplemental contours) had to be “thickened” so they could be viewed in a digital version.   You can also see looking at the 1892 edition 1:62,500 scale map that the line weights for contours were much heavier than in the newer 1:24,000 scale quadrangles. 

Sent from my digital telegraph key
Jim Stapleton, retired USGS 2011


On Apr 25, 2021, at 06:22, NW Mailing List <nw-mailing-list at nwhs.org> wrote:


Here are some additional maps that may help or may throw a wrench in the works. Per the U.S. Geological Survey, there are/were two separate locations -- Maybeury and Switchback. Per the maps, it appears that Switchback may have been named for the switchback on the branch on the south side of the main line that went west, then came back east then south to climb to a mine up an unnamed hollow (now the route of Peeled Chestnut Rd.). It also appears that there was another branch that came off the same westbound main a little to the east and dropped down to go up that same hollow at a lower level. The 1909 map also shows a branch going north up Turkey Gap.

To the east in Maybeury, there is another branch that drops down into the creek bottom, then goes in multiple directions east, with one line going under the main line and running up along Little Fork through and beyond "downtown" Maybeury. Unfortunately, the topo maps are fuzzy on details due to everything crammed on there (roads, buildings, tracks, contour lines, etc.).

These maps were downloaded from the historical topo map repository at the University of Texas:
http://legacy.lib.utexas.edu/maps/topo/west_virginia/

They (and more) are also available through the USGS Historical Topographical Map Explorer site at:
https://livingatlas.arcgis.com/topoexplorer/index.html

Bruce in Blacksburg



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