Learn more about how the Cal Poly Humboldt Library can help
support your research and learning needs.

Stay updated at Campus Ready.

Skip to Main Content

Maps and Atlases


This research guide serves as a guide to print topographic maps available in the HSU Library Atlas and Map Collection and digital maps that can be viewed on the Internet or downloaded for personal viewing or use in GIS programs.

Table of Contents:

Other Places to Look:

Topographic Map

Topographic Mapping

Guides to Topographic Mapping

  • National Mapping Agencies Contact Information (United Nations)
  • World Mapping Today (Pary and Perkins) 2002 (ref GA 105.3 P37 2002) On a country-by-country basis details the status of national mapping programs, including major thematic and topographic map products. Includes graphic indexes for many series.

Understanding Topographic Maps

Topographic Maps provides an overview of U.S. Geological Survey topographic maps including their characteristics, production, and history. Maps for America (US Geological Survey) 1981 (Docs I 19.2:M32/12 1981) includes detailed information on the characteristics, natural features, cultural features, boundaries, names, marginalia, projection, reference systems, and geodetic control found on topographic maps. In 1991 the USGS completed its analog map coverage of the 48 contiguous states of the United States at a 1:24,000 scale. This coverage includes more than 55,000 7.5-minute quadrangles. For additional background information on print and digital production see 125 Years of Topographic Mapping.

  • Topographic Map Symbols: 

    Topographic Map Symbols (paper copies kept in the vertical filing cabinets in the Map and Atlas Collection) lists symbols found on USGS topographic maps. Information about specific survey control points or benchmarks found on each topographic map is maintained in the NGS Data Sheets database maintained by the National Geodetic Survey.

  • Topographic Map Grids

    Four grid systems are shown on most USGS topographic maps:

    1. Latitude/longitude - see Latitude and Longitude for an an introductory description. Geocoder will convert an address or zip code to lat/long coordinates.
    2. Public Land Survey grid - see The Public Land Survey System (PLSS) for an introduction to the public land survey and a map of the 34 principal meridians and base lines in the United States.

      In California there are three base meridians--San Bernadino, Mt. Diablo, and Humboldt. The initial point of the Humboldt Meridian was established on the summit of Mt. Pierce on October 6, 1853 by surveyor Colonel Henry Washington.

      The Township Geocoder converts Latitude and Longitude (Lat/Long) values into Township, Range and Section values; and Township, Range and Section values can be converted into polygon centroids in Lat/Long format. 

      Township and Range-Public Land Survey System on Google Earth displays townships, one-mile sections and quarter-sections on Google Earth. You can enter a township and range and "fly" to the location in Google Earth. You can also "Convert Township, Range, and Section to Latitude and Longitude" and "Convert Latitude and Longitude to Township and Section".
    3. Universal Transverse Mercator (UTM) - see Universal Transverse Mercator (UTM) Grid for additional information.
    4. State Place Coordinate System (SPCS) - see State Plane Coordinate System for additional information. Gridding may be based on the North American Datum of 1927 (NAD27) or the more recent North American Datum of 1983 (NAD83).

  • Topographic Map Placenames: 

    Geographic Names Information System (U.S. Geological Survey) Contains information on 2 million physical and cultural geographic features in the United States. The database includes all names appearing on USGS 1:24,000 topographic maps, USFS maps, National Ocean Service nautical charts, National Park Service maps and other sources. Includes over 100,000 historical entries for places that no longer exist. Information provided for each entry includes the name as recognized by the U.S. Board on Geographical Names, type of feature, country, geographic coordinates, and the USGS topographic quadrangle on which the feature is found. Each entry includes links to more than 10 mapping services, e.g., Google Maps, that will display the feature.

  • Data Set Number (DSN)

    These alpha-numeric codes are used in naming Digital Raster Graphics (DRGs) which are scanned images of USGS topographic maps. DRGs are used in GIS programs or can be viewed as a standalone file using free viewing software, e.g., DLGV32Pro. As an example 1:24,000 (7.5 minute) DRGs are gridded into 1 degree blocks of longitude and latitute, each containing 64 DRGs in 8 rows and 8 columns. Each DRG is assigned a Data Set Name (DSN) using this grid, e.g., 40124E1 for Eureka. DSNs are based on the older convention for coding standard USGS quadrangles with a unique map reference code. Here is a Excel file correlating California quadrangle names with DRG Data Set Numbers.

Indexes to Topographic Maps

The following options are available for finding the names and availability of topographic maps:

Starting Information Site
Placename (city, county, feature)
Zip Code
Clickable US Map
Map Name
State List (alphabetical)
Lat/Long Coordinate 
UTM Coordinate 
State Plane Coordinate
MapMart or USGS Store
OmniMap or MapMart 
Stanford Univ Library or MapMart or USGS Store
MapMart or USGS Store or OmniMap
State Topographic Map Lists

Paper Maps in the HSU Library

  • Large- scale (detailed) topographic maps---U.S. Geological Survey quadrangles

Maps Available: 

The Library keeps the most recent edition of US Geological Survey 1:24,000 scale (7 1/2 minute) topographic quadrangles and all older 1:62,500 scale (15 minute) topographic quadrangles for California. Also integrated alphabetically into the topographic map collection are 1:50,000 scale maps produced by the National Imagery and Mapping Agency and northwestern. Superceded topographic maps and 1:24,000 scale orthophotoquad maps of northwestern California are located in the Humboldt Room.


Maps are filed alphabetically by the quadrangle name.


The California Topographic Map Index is displayed in the Atlas and Map Collection and is a gridded index for the entire state. In addition the indexes above can be used to find a quadrangle name, depending on what you know as a starting point.

  • Historical Topographic Quadrangles:

    Available on microfilm (MF 2370) is a complete historical collection of California, Oregon, Nevada, and Arizona topographic quadrangles dating from 1884 to 1972 compiled by the USGS and other federal agencies. The Map Index to Topographic Quadrangles of the United States, 1882-1940 (ref GA 405 M64 1985) provides indexing for this microfilm set. Obsolete USGS topographical maps of California (Los Angeles Public Library) contains an alphabetical list of historical California topos along with dates of publication.

  • Intermediate-scale topographic maps
    • U.S.--1:250,000 (US Geological Survey) (G 3700 s250 U5) Series of 600 topographic maps covering all 50 states. See index in the Map Filing Cabinet
    • U.S.--1:100,000 (US Geological Survey) (G 3700 s100 U5) Topographic map series covering the contiguous U.S. See index in the Map Filing Cabinet
    • Joint Operations Graphic (US National Imagery and Mapping Agency) (G 3200 s250 U5) Topographic map series at a scale of 1:250,000. See index in the Map Filing Cabinet. Library has coverage mainly of Europe.
    • Americas--1:250,000 (G 3290 s250 P3) Map series at a scale of 1:250,000 published by individual Latin American countries and coordinated by the Pan American Institute of Geography and History. See index in the Map Filing Cabinet.
    • In addition search individual countries for intermediate-scale topographic map series available for that country.
  • Small-scale topographic maps
    • Tactical Pilotage Chart (US National Imagery and Mapping Agency) (G 3201 P6 s500 U5) Aeronautical chart series at a scale of 1:500,000 showing topographic features by color relief and contouring. See index in the Map Filing Cabinet.
    • International Map of the World (G 3200 s1000 U5) Older series of 700 maps at a scale of 1:1,000,000 published by individual countries and coordinated by the United Nations. See index in the Map Filing Cabinet.
    • Operational Navigation Chart (US National Imagery and Mapping Agency) (G 3201 P6 s1000 U5) Aeronautical chart series at a scale of 1:1,000,000 showing topographic features by shaded relief and contouring. See index in the Map Filing Cabinet.

Digital Maps On the Internet


Listed below are sites that allow you to interactively view topographic maps on the Internet, download digital topographic maps for personal viewing or download digital topographic maps for use in GIS programs. For maps viewed online you may be able to print, download, link or email them. You can also use free screen capture software, e.g., Scrennpresso or Jing to capture the screen image of a viewed map.

  • United States--Current
    •  USGS Digital Topographic Maps

      Map formats:

      • US Topo maps are the new generation of USGS digital topographic maps. Maps are designed to look, feel and perform like traditional print topographic quadrangles. Each map is constructed in GeoPDF format from key layers of geographic data – orthoimagery, roads, geographic names, contours and hydrographic features. A free TerraGO toolbar plug-in for theAdobe Reader is available that allows you to view coordinates, measure distance and area, zoom to a coordinate and connect to a GPS device. For further information see US Topo Users Guide.
      • Digital Raster Graphics (DRGs) are scanned images of traditional USGS topographic maps. Downloaded DRGs in TIFF format can be used in GIS programs or can be viewed as a standalone file using free viewing software, e.g., DLGV32Pro. For GIS applications both the TIFF and the companion TFW format must be downloaded.

      Map availability:

      • Earth Explorer Search and download DRGs in TIFF format. Search by address, placename, or use a Google Maps interface. These are original DRGs that include all map collar information.
      • National Map Viewer and Download Platform Search and download collarless DRGs in TIFF format or 1:24,000, 1:100,000 and 1:250,000 topographic maps of the United States, including US Topo maps. Search by placename or use a clickable map.
      • USGS Store Search, download or order 1:24,000, 1:100,000 and 1:250,000 topographic maps of the United States and Antarctica in GeoPDF format. Includes current US Topo maps and historical topographic maps.
    • ACME Mapper (AMCE Laboratories) Use a Google Maps interface to navigate to a location anywhere in the world, or enter an location name (US street address or zip code, city name anywhere in the world or latitude/longitude. Display options include a street map, topographic maps (US only), terrain, aerial photography (US only), satellite imagery, and NEXRAD color imagery. Options allow one to change coordinates (lat/long, UTM, geotags) and track coordinates.
    • FSTopo 7.5' Quad Maps (US Forest Service) GeoPDf and GeoTiff 1:24,000 topographic maps covering national forests and national grasslands.
    • Google Earth applications. Requires installation of Google Earth. Some of these applications are linked to web mapping services that only load a small area at a time. Each time you stop moving the view you will need to wait a few seconds for the new area to load.
      • Insta-Topos with WMS (GELessons) Follow these direction to set up your own USGS topographic map layer in Google Earth.
      • Map Finder for Google Earth (Digital Data Services) Gridded index to all USGS 1:24:000 topographic maps. For each quadrangle you can download a free TIFF image by clicking on the bubble icon.
      • USGS Quadrangles (QUADS) (Metzger & Willard, Inc.) Gridded index to all 73,000 USGS topographic quadrangles. For each quadrangle you can download a free GeoPDF map linked from the USGS Store. Other available layers include grayscale and color shaded relief maps, topographic-bathymetric maps, black-and-white orthophotos, and urban areas color orthoimagery. See USGS Quadrangles in Google Earth for additional information.
      • USGS Topographic Map Overlay (3D Solar) Launches a seamless layer of USGS topographic maps.
      • USGS Topographic Maps for Google Earth (Google Earth Library) Gridded index to USGS 1:24,000 scale topographic maps. Click on the map name in the blue grid to display the topographic map.
    • Map and GIS Data By US State (Libre Map Project) Download free DRG's of 1:24,000 scale quadrangles in both TIFF and TFW formats. Display each state by quadrangle name or search by placename.
    • Maptech MapServer: Topographic Maps (Maptech) View a seamless collection of USGS 1:24,000, 1:100,000, and 1:250,000 topographic maps for the contiguous United States. Search for maps by placename, zip code, or geographic coordinate. You can pan to adjacent maps and display each map at 100% or 50% resolution. Print, save, or email what is displayed.
    • MSR Maps (Microsoft) (formerly Terraserver-USA) View a seamless collection of USGS topographic maps for the United States. Screen viewing area has three settings--small, medium, and large. Map resolution can be adjusted from 2 meters to 128 meters. Search by address, placename, geographic coordinate, or by clicking on an image map. Maps can be downloaded in JPEG format, printed, emailed or linked. Also links to orthophotoquad images and natural color relief maps which cover the same geographic area.
    • MyTopo: Online Topo Map Viewing (MyTopo) View a seamless collection of topographic maps of the United States and Canada. Use a Google Maps interface or search by city, town, zip code, address, lat/long or geographic feature name. Link or print what is displayed.
    • USA Topo Maps (ESRI) Interactive mapper provides detailed USGS topographic maps for the United States at 1:250k, 1:100k, and 1:24k scale levels. Map can be viewed with the default ArcGIS map viewer or ArcGIS Explorer.
    • United States Topographic Maps 1:250,000 (University of Texas Perry-Castaneda Map Library) Contains scanned images in this series date from the 1940s to the present.


  • United States--Historical

The USGS Historical Topographic Map Collection includes 180,000 historical topographic quadrangles produced by the USGS since the inception of the topographic mapping program in 1884.

Other sites containing historical topograhic maps include:

    • Topographic Map Sites (University of Texas Perry-Castaneda Map Library) Master directory of sites, arranged by state, that contain historical topographic maps.
    • Coastal Topographic Sheets (T-sheets) (US Coast Survey) Highly detailed topographic maps of the shorelines and waterways of the United States. Maps date from 1834 to 1911. The "T-Sheets" contain historical information on such features as locations of buildings and detailed descriptions of shorelines.
    • General Land Office (GLO) Survey Plats and Field Notes (US Bureau of Land Management) Survey plats and field notes are the official documents resulting from the survey of federal public domain lands by the US General Land Office. From an historical perspective survey plats and field notes give a picture of the land during its original settlement and are now used extensively by title companies, surveyors, historians, genealogists, biogeographers and other researchers. Survey plats in many instances are the first maps of an area and show the locations of rivers, early settlements, roads, forts, and trails as well as topographic features.

      Originating with the Land Ordinance of 1785 the initial purpose of the survey was to divide the vast public domain into lots that could be sold to raise funds for the federal government and to encourage settlement of the public domain. Land title was transferred from the federal government to individuals through land patents. Survey work was done using the Public Land Survey System (PLSS) which divided the public domain into six-mile square townships and one-mile square sections. The PLSS was utilized in 30 states and resulted in 133,000 survey plats and 2.75 million pages of field notes that date from the 1820s.

      The field notes created by surveyors describe in detail each mile of line surveyed; monuments placed; terrain over which they passed; and nature of the soil, vegetation and timber, salt licks, and other items of economic interest. Survey plats are the graphic representation of the information contained in the field notes. They show the PLSS boundaries (e.g. section boundary lines) and some of the physical and cultural features found in the notes.

    • Historic Topo Maps (Google Earth Library) Includes over 2,000 historic USGS topographic maps available in various scales dating back to the late 1800s in some areas. Currently, most of the coverage is in the western United States and California. Requires installation of Google Earth.
    • Historic USGS Maps (Broer Map Library) Contains a selection of historical topographic maps for most states.
    • Historic USGS Maps of New England & NY (University of New Hampshire Library) Includes historical topographic maps for Conneticut, Maine, Massachusetts, New Hampshire, New York, Rhode Island and Vermont.
    • Online Topographic Map Collections (University of Texas Perry-Castaneda Map Library) In progress collection of pre-1945 USGS topographic maps, arranged by state. See Scanning Status Map for progress.
    • Southwest U.S. Geological Survey Maps (Fort Lewis College Center of Southwest Studies) Includes images of 61 early USGS topographic maps of the four corners region of Colorado, New Mexico, Arizona and Utah.
  • Other Countries and Regions
    • Toporama (Canadian Center for Topographic Information) Contains raster images that correspond in part to 1:250,000 and 1:50,000 Canadian National Topographic Data Base maps; and ortho images converted from Landsat 7 imagery. Search using a clickable map or enter a geographic coordinate. Maps are also searchable using GEOSCAN. On the advanced search page select the "GS Topographic Maps" option in the Series search box.
    • Digital Topographic Map Sets (UC Berkeley Earth Sciences and Map Library) Contains index graphics and scanned images of Soviet Union topographic map sets for individual countries at scales of 1:50,000 to 1:200,000.
    • International Map of the World 1:1,000,000 (University of Texas Perry-Castaneda Map Library)
    • Online Topographic Map Collections (University of Texas Perry-Castaneda Map Library) Collection of scanned maps arranged by continent. Scale varies by country.
    • U.S. Army Map Service Topographic Maps (US Army Map Service) Includes approximately 450 topographic map series produced by the AMS and its successor agencies-- Defense Mapping Agency, National Imagery and Mapping Agency, and National Geospatial-Intelligence Agency. These series were distributed to participating map libraries beginning in 1945. These maps are now historical in nature in that they reflect the political and cultural features of the time period in addition to the topography. Scales vary but many are 1:250,000. Some series still offer the most detailed topographic map coverage for the area. The HSU Library became a depository for current print maps in 1976. Series received include the Joint Operations GraphicTactical Pilotage Chartand Operational Navigation Chart listed above.


      Digital Collections

    • World Topographic Map (ESRI) Interactive mapper includes boundaries, cities, water features, physiographic features, parks, landmarks, transportation, and buildings. Scale varies by country. Map can be viewed with the default ArcGIS map viewer or ArcGIS Explorer.