Topographic Maps
See also: Map Collection | Map Basics
Topographic maps show the shape and elevation of the land, usually by contours. They usually include both natural features (e.g. rivers, mountains, valleys) and manmade features (e.g. roads, major buildings, dams). The wide range of information provided by topographic maps make them extremely useful for research. They are also heavily used for recreational purposes such as finding campgrounds or trails.
The United States Geological Survey (USGS) is the agency responsible for most of the topographic mapping of the United States. They produce maps at a variety of scales, including 1:24,000; 1:100,000; and 1:250,000. The maps are published as quadrangles ("quads"). Indexes are available to help locate the necessary quad.
More information is available from:
Maps for America (Map Index Table & Gov Pubs/US I 19.2:M 32/12/987) includes information about the history, characteristics and production of US Geological Survey maps.
U.S. Geological Survey Topographic Maps USGS.
USGS Maps USGS.
Topographic Map Symbols USGS.
How to find the maps
Topographic maps are located in the Map Collection, which is located in the Reference Services Division (1st floor, Library Addition). Assistance is available during reference hours by coming in person or by calling (619) 594-6728.
The Map Collection includes these major USGS series:
1:24,000
See a Sample map.
This series, also called 7.5 minute or 7.5', is the most detailed (1 inch = 2,000 feet) of the topographic series of the United States. It is also the most heavily used in the Map Collection. The SDSU Library receives all quads for the United States. The library also keeps previous editions for states west of the Mississippi, which are useful for historical research.
Index: Use the appropriate state index on the Map Index Table to get the name of the quad(s) you're interested in. The Geographic Names Information System (GNIS) from USGS also indexes these maps. Search results give the name of the USGS 7.5' topo quad that covers a given feature.
Maps: Filed in the USGS map drawers alphabetically by quad name within each state. Maps for Puerto Rico, U.S. Virgin Islands, and central Pacific islands are available at various scales and are filed in the map drawers for those areas. Note: the quads for San Diego county are filed in the San Diego drawers.
1:63,360 Alaska
See a Sample map.
This series, also called 15 minute or 15', is produced for the state of Alaska. The SDSU Library owns all Alaska quads published to date.
Index: Use the Alaska index on the Map Index Table to get the name of the quad(s) you're interested in.
Maps: Filed in the USGS Alaska map drawers alphabetically by quad name.
1:100,000
See a Sample map.
The Library receives all current maps for the United States, but does not have previous editions.
Index: Use the appropriate state index on the Map Index Table to get the name of the quad(s) you're interested in.
Maps: Filed in the USGS map drawers alphabetically by quad name within each state. Note: the quads for San Diego county are filed in the San Diego drawers.
1:250,000
See a Sample map.
The Library has all current maps for the United States, but does not have the previous editions.
Index: Use the appropriate state index on the Map Index Table to get the name of the quad(s) you're interested in.
Maps: Filed in the USGS map drawers alphabetically by quad name within each state.
Note: the quads for San Diego county are filed in the San Diego drawers.
State
See a Sample map.
The Library has all current editions of the state maps.
Maps: Filed in the map drawers by state. Note: these are not kept with the other USGS maps. They are filed in the folders for the states.
