The USGS uses every tool available to make accurate and up-to-date maps. This includes boats and binoculars, as well as airplanes, satellites, crowd- sourcing, and lasers! We also use maps every day to help understand our environment.
Why a map? They say pictures are worth a thousand words, a map is a specific kind of picture of a particular area. The USGS uses different kinds of maps to present its science in a clear picture, including hand-drawn, digitally drawn, and overhead-image maps.
Cartography, the science of making maps, is a very old science. The USGS has been a leader in the building of maps and creating new types of maps for over 100 years! We have cartographers, geographers, geologists, and other scientists making and using maps every day as well as scientists working on new types of maps and new ways to represent and understand geographic data and the natural resources of the United States.
Earth Explorer
topoBuilder
National Map Viewer
Federal Priority Streamgages Mapper
Science in Your Watershed
National Groundwater Monitoring Network
USGS Library Resources
The USGS library has created a series of guides on a variety of topics.
Maps and Mapping: Overview
Land Survey Benchmarks: Introduction
USGS Library: Library Guides
USGS Library Collections
Science
Principal Aquifers of the United States
Principal Aquifers of the United States
What is declination?
At most places on the Earth's surface, the compass doesn't point exactly toward geographic north. The deviation of the compass from true north is an angle called "declination" (or "magnetic declination"). It is a quantity that has been a nuisance to navigators for centuries, especially since it varies with both geographic location and time. It might surprise you to know that at very high latitudes...
Where can I find a topographic map symbol sheet?
Like topographic maps, topographic map symbols have evolved over time. There is no single document that describes all of the symbols used on all USGS topographic maps since they were first created. Maps published 2013-present: US Topo maps have a symbol sheet attached to the map file (PDF format only). Open the PDF file in Adobe Acrobat and click on the paperclip icon. Maps published 1947-2009...
What is the National Geologic Map Database?
The National Geologic Map Database (NGMDB) is an archive of geoscience maps (including geology maps), reports, and stratigraphic information for the United States. The NGMDB contains information on more than 90,000 maps and related geoscience reports published from the early 1800s to the present day, by more than 630 agencies, universities, associations, and private companies. Much of the content...
How can I find survey benchmark and triangulation station information?
Most survey marks were set by the U.S. Coast & Geodetic Survey (now called the National Geodetic Survey); information for those marks is available online. For further assistance, contact the National Geodetic Survey at 301-713-3242 or ngs.infocenter@noaa.gov. For information about marks set by the USGS, contact the National Geospatial Technical Operations Center at tnm_help@usgs.gov. Learn more...
How are different map projections used?
The method used to portray a part of the spherical Earth on a flat surface, whether a paper map or a computer screen, is called a map projection. No flat map can rival a globe in truly representing the surface of the entire Earth, so every flat map misrepresents the surface of the Earth in some way. A flat map can show one or more--but never all--of the following: True directions True distances...
- Overview
Why a map? They say pictures are worth a thousand words, a map is a specific kind of picture of a particular area. The USGS uses different kinds of maps to present its science in a clear picture, including hand-drawn, digitally drawn, and overhead-image maps.
Cartography, the science of making maps, is a very old science. The USGS has been a leader in the building of maps and creating new types of maps for over 100 years! We have cartographers, geographers, geologists, and other scientists making and using maps every day as well as scientists working on new types of maps and new ways to represent and understand geographic data and the natural resources of the United States.
Earth ExplorerEarth ExplorertopoBuildertopoBuilderNational Map ViewerNational Map ViewerFederal Priority Streamgages MapperFederal Priority Streamgages MapperScience in Your WatershedScience in Your WatershedNational Groundwater Monitoring NetworkNational Groundwater Monitoring NetworkUSGS Library Resources
The USGS library has created a series of guides on a variety of topics.
Maps and Mapping: OverviewMaps and Mapping: OverviewLand Survey Benchmarks: IntroductionLand Survey Benchmarks: IntroductionUSGS Library: Library GuidesUSGS Library: Library GuidesUSGS Library CollectionsUSGS Library CollectionsScience
Principal Aquifers of the United States
This website compiles USGS resources and data related to principal aquifers including Aquifer Basics, principal aquifers maps and GIS data, and the National Aquifer Code Reference List. - Publications
- Science
Principal Aquifers of the United States
This website compiles USGS resources and data related to principal aquifers including Aquifer Basics, principal aquifers maps and GIS data, and the National Aquifer Code Reference List. - Data and More
- Multimedia
- FAQ
What is declination?
At most places on the Earth's surface, the compass doesn't point exactly toward geographic north. The deviation of the compass from true north is an angle called "declination" (or "magnetic declination"). It is a quantity that has been a nuisance to navigators for centuries, especially since it varies with both geographic location and time. It might surprise you to know that at very high latitudes...
Where can I find a topographic map symbol sheet?
Like topographic maps, topographic map symbols have evolved over time. There is no single document that describes all of the symbols used on all USGS topographic maps since they were first created. Maps published 2013-present: US Topo maps have a symbol sheet attached to the map file (PDF format only). Open the PDF file in Adobe Acrobat and click on the paperclip icon. Maps published 1947-2009...
What is the National Geologic Map Database?
The National Geologic Map Database (NGMDB) is an archive of geoscience maps (including geology maps), reports, and stratigraphic information for the United States. The NGMDB contains information on more than 90,000 maps and related geoscience reports published from the early 1800s to the present day, by more than 630 agencies, universities, associations, and private companies. Much of the content...
How can I find survey benchmark and triangulation station information?
Most survey marks were set by the U.S. Coast & Geodetic Survey (now called the National Geodetic Survey); information for those marks is available online. For further assistance, contact the National Geodetic Survey at 301-713-3242 or ngs.infocenter@noaa.gov. For information about marks set by the USGS, contact the National Geospatial Technical Operations Center at tnm_help@usgs.gov. Learn more...
How are different map projections used?
The method used to portray a part of the spherical Earth on a flat surface, whether a paper map or a computer screen, is called a map projection. No flat map can rival a globe in truly representing the surface of the entire Earth, so every flat map misrepresents the surface of the Earth in some way. A flat map can show one or more--but never all--of the following: True directions True distances...