A Guide to Olin Library Holdings
Since the late 19th century, the United States Geological Survey has been producing topographic quadrangle maps. These detailed maps show the shape and elevation of the land, transportation networks, drainage patterns, vegetation, and buildings. These maps are used for a variety of purposes, including industrial site selection, highway planning, and recreation, and they are also a valuable source for local history.
7-1/2 Minute Quadrangles
The 7-1/2 minute topographic quadrangle maps, or topo quads, for each state are filed around the perimeter of the Map Room, starting on the left as you enter. They are arranged alphabetically by state, and then alphabetically by quadrangle name. Labels on each drawer show the alphabetic range within.
Index maps are filed at the beginning of each state's maps. Each small square on the index map is identified by a quadrangle name. If you already know approximately where the area is for which you want a map, simply locate the quadrangle on the state index map. If you are looking for a map of a particular place, but are not sure where the place is, consult an indexed road map or use the Omni Gazetteer CD-ROM to find the place's location.
Date of Situation
Maps are revised or replaced periodically to keep them accurate, complete and suitable for the intended use. The Olin Library Map Collection tries to retain one copy of each edition of each U.S.G.S. topographic map for the entire United States. The actual date that the air or ground survey of the area took place will be printed at the bottom of the map, along with other information about that map's publication history.
The microfiche set Map and chart information system provides a record of all historical editions of large- scaled topographic mapping of areas in the United States. It is indexed both alphabetically by quadrangle name and geographically by latitude and longitude. (MAPS G 3701 A2 1993 M37)
Brochures which explain the symbols on topographic maps are available in the Map Room.
Intermediate & Small Scales
Two other important U.S.G.S. topographic map series are the 1:100,000-scale and the 1:250,000- scale quadrangle maps. These are cataloged as G3700s 100 U5 and G3700s 250 U5 respectively. Index maps are filed at the beginning of each series.
For more information:
Moffat, Riley Moore. Map Index to Topographic Quadrangles of the United States, 1882-1940. Santa Cruz: Western Association of Map Libraries, 1986.
(MAPS GA 405 M68)
Thompson, Morris Mordecai. Maps For America: Cartographic Products of the U.S. Geological Survey and Others. Reston, VA: U.S. Geological Survey, 1988.
(MAPS GA 405 T47 1987)