Page Content. The maps are grouped into seven sections: Colony and Commonwealth; Counties; Townships; Cities and Boroughs; Boundaries, Topography, Geology, Parks; Transportation including Indian trails, roads and turnpikes, rivers and streams, canals, railroads, air routes, etc. Canal Commissioners Map Books - Map books prepared by engineers at the request of the Commissioners for the purpose of illustrating routes for the various divisions of the Pennsylvania Canal system or to illustrate the final layout after construction.
Few of these show routes as they were finally laid out and operated and are primarily preliminary plans. In addition to providing overall layouts for how the finished canals were intended to look, they also contain numerous drawings of dams, raft chutes, feeders, reservoirs, locks, lock gates, lock houses, aqueducts, towing path bridges, and waste weirs illustrating how the system was intended to work.
This benefits non-specialist map users, as well as applications that need traditional maps. The goal of the HTMC, which started in , is to provide a digital repository of USGS , scale and larger more detailed maps printed between the inception of the topographic mapping program , and Currently, there are more than , maps in the HTMC and the collection continues to grow.
NGP is accurately cataloging and creating metadata to accompany high-resolution, georeferenced digital files of each of these printed maps. However, additional formats are now offered for evaluation and use through topoView. These include:. The GeoTIFFs are generated at true scale, allowing users to plot the map at the intended map scale in cases where a hard copy is needed.
To view the metadata file, simply open it in a text editor, web browser, or application that supports XML. Build — 2. This mapping was done at different levels of detail, in order to support various land use and other purposes. As the years passed, the USGS produced new map versions of each area. The most current map of each area is available from The National Map.
TopoView shows the many and varied older maps of each area, and so is especially useful for historical purposes—for example, the names of some natural and cultural features have changed over time, and the historical names can be found on many of these topographic maps.
Geologic and topographic mapping have a long tradition together see report. Geological Survey. Chris served as the topoView development lead.
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