Map Reference Update David J. Bertuca
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US Topographic Map SearchesWhat is a topographic map? This type of map shows "topography" or surface features of the landscape being depicted on the map. Usual features include elevations, contours of elevation, natural and man-made features, etc. Underwater "topography" is called "bathymetry" and shows terrain on the bottom of water bodies. If the water were drained away, then the map would show "topography." Searching for bathymetric map in BISON is just like searching for topographic maps. Topographic Maps: How to Use and Read. This page will describe all that you need to know, including symbols, how to find in BISON, examples, where to purchase, and more. How do you locate topographic maps? This page explains how to locate and use topo map indexes for USGS topographic maps of the United States and dependencies, and how to use BISON to find topo maps worldwide. It also provides links to other topo map resources. For US topographic maps, the series is divided into two types: current and historic. This is USGS semantics for topos that are pre-1948 and post-1948. The historic topos were drawn at the scale of 1:63,360, while most current maps are 1:24,000-scale. For some states, specific areas were drawn at 1:25,000-scale (1cm = 1km), while Alaska, because of its size, is completed in several main scales. The entire state was not drawn to the same larger-scale as the 48 conterminous states. The 24,000-scale is 4 times greater in detail than the historic topos. Comparing these to the older maps, four current maps put together show the same area as 1 historic map. This provides more data and resolution than previously available. For the United States, these are generally the largest scale available (exceptions being some major city maps, commercially-, or municipally-produced maps, etc.).
This is all you need to find one-third of the maps in the Collection. Similar map indexes exist for Canadian government-produced topographic maps. For New York State, a digitized version of the index is on the Map Collection website. You can view this, then select a region to enlarge to find the map titles you need. Also on the Map Indexes page, are links to other sites that offer electronic map indexes for NYS. Other states are online from USGS and other sources, however, no complete set exists online at this time. Some commercial sites are also providing access to e-versions of the indexes. To acquire digital topos for other states, Use the Guide: Locating and downloading United States Geological Survey Topographic Maps to help you locate topo maps, in paper and digital formats. Map indexes for other countries also may be found online to assist in locating maps. |
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Searching for NYS Historical Topographic MapsHistoric New York Topographic Maps (pre-1950) may be located at several sites (which also have earlier maps for New England states, among others). The maps were drawn along the same standards as the current topos, which are larger-scale editions using the same base data. They are 4 times smaller in scale than the current 1:24,000-scale topos.
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Digital Sanborn Map searching and useSanborn and other fire insurance maps were produced from the second half of the nineteenth century onward and provide a wealth of detail on human structures in America. For historians, planners, anthropologists and archaeologists, genealogists, and for research in almost every field today, these are the most popular cartographic materials available. Their value is beyond almost every other format of this data. Collections that hold original copies of these types of maps have the ultimate in primary source material; those fortunate enough to be able to refer to the originals are rewarded with a rich, colorful view of specific periods of time and location. For the rest of us, digitized facsimiles are the next best thing, though they fall short of the originals in their lack of color and aesthetics. But for most research and use, these serve the user very well. UB has a subscription to New York State digital Sanborn maps. Go to the page that describes Sanborn maps and there are resources and links to other collections of these, as well as instructions on using the digital product. For the present, direct users to this temporary Sanborn Instructions guide that I set up to assist in navigating the database.
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David J. Bertuca, Map Librarian, Arts & Sciences Libraries Last Modified: 25 April 2013 |
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USGS Map Indexes
The indexes are maps that have a grid showing the name and location of each map for that state. Simply locate the place that you want to find, then look up the name that is given in the map drawers.
