TopoView from the USGS is Available

By Susan Smith


TopoView provides one of the USGS’s most important and useful products, the topographic map, in a way that is easy to use, accessible and provides wonderful historical map data.

In 1879, the USGS began to map the Nation’s topography. Just like in a lot of modern mapping, this topographical mapping was done at different levels of detail, as needed to support various land use, exploration and other purposes. The collection of maps deepened and expanded as the years passed, with the USGS producing new map versions of each area. The most current maps are available fromThe National Map. For those users who need historical reference maps, TopoView shows the many and varied older maps of each area. TopoView also takes into account the fact that the names of some natural and cultural features have changed over time, and the ‘old’ names can be found on these historical topographic maps.

According to USGS materials, this interface was created by the National Geologic Map Database project (NGMDB), in support of topographic mapping program managed by the National Geospatial Program (NGP). Geologic mapping and topographic mapping at the USGS have a long tradition together (see 1888 report). The NGMDB project is proud to assist the NGP in bringing these maps to the Web.

TopoView is packed with new features as well as downloadable file formats such as jpeg, GeoTIFF, and KMZ. The maps shown through topoView are from the USGS’s Historical Topographic Map Collection(HTMC). The goal of this scanning, which started in 2011, is to provide a digital repository of USGS 1:250,000 scale and larger (more detailed) maps printed between 1884 (the inception of the topographic mapping program), and 2006. Currently, there are more than 178,000 maps in the HTMC. The NGP is accurately cataloging and creating metadata to accompany high-resolution, georeferenced digital files of each of these printed maps. At present, these maps are offered as GeoPDFs, through The National Map and the USGS Store. However, additional formats are now being offered for evaluation and use through topoView to include:
GeoTIFF – The GeoTIFF files are a compressed, 300 dpi TIFF image format, with embedded georeferencing information so that the map can be used directly in a Geographic Information System (GIS). 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.
JPEG – The high-resolution JPEGs, or ‘Browse JPEG’ format are useful for getting a quick view of the map in order to find place names or simply explore the map area without the need for downloading a large file.
KMZ – The KMZ format is a compressed form of the KML format which is used for displaying the maps in Google Earth.

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