A diagram at the bottom of most USGS topographic maps shows three north arrows--true north, grid north, and magnetic north--and the angles between them. Some maps, especially very old maps, do not have this diagram.
True north, also called geodetic north or geographic north, is the direction of the line of longitude that bisects the quadrangle. All longitude lines converge to points at the north and south poles. The star symbol in the diagram indicates true north.
Magnetic north (MN) shows the direction a magnetic compass would point at the time the map was published. The direction of magnetic north varies over time and with the position on the earth's surface, so magnetic declination values on old maps might no longer be accurate. Magnetic declination values shown on current maps are obtained from NOAA's National Geophysical Data Center.
Grid north (GN) is the direction of a plane grid system, usually the grid associated with the map projection. On current US Topo maps, the projection is Transverse Mercator and the plane grid is Universal Transverse Mercator (UTM). All US Topo maps have a 1,000-meter UTM grid included on the map; the angle at which this grid meets the map projection line visually shows the difference between true and grid north. Historical topographic maps might relate grid north to other grid systems. The difference between true north and grid north is an inherent effect of transforming the earth's spherical surface to a plane surface. The size of this difference for a particular map depends on the projection and the map location relative to the projection origin.
Related Content
How do I find, download, or order topographic maps?
The U.S. Geological Survey (USGS) has been the primary civilian mapping agency of the United States since 1879. USGS topographic maps have been published at many scales, but 1:24,000 (also referred to as a 7.5-minute quadrangle) has been the standard topographic map scale since 1947. For Alaska the standard scale is 1:25,000. All dates and all scales of our topographic maps can be freely...
Are USGS topographic maps copyrighted?
All topographic maps produced by the U.S. Geological Survey (USGS) are in the public domain and are not copyrighted except for the following three cases that apply only to US Topo maps (produced 2009-present): Most maps in the period 2010-2016 contain commercially licensed road data (see note below). Orthoimages in Alaska are commercially licensed. Orthoimages in Hawaii were commercially licensed...
Can I still get the older topographic maps?
Yes. Topographic maps originally published as paper documents between 1884-2006 have been scanned and published as the USGS Historical Topographic Map Collection. Download our historical topographic maps and our more current US Topo maps (published 2009-present) free of charge using TopoView (GeoPDF, GeoTIFF, JPEG, and KMZ formats) or using the USGS Store’s Map Locator (GeoPDF format). Order paper...
What is a topographic map?
The distinctive characteristic of a topographic map is the use of elevation contour lines to show the shape of the Earth's surface. Elevation contours are imaginary lines connecting points having the same elevation on the surface of the land above or below a reference surface, which is usually mean sea level. Contours make it possible to show the height and shape of mountains, the depths of the...
Where can I find indexes of USGS topographic maps?
View map indexes on these interactive maps (you must zoom in to see the index lines and map names): Map Locator on the USGS Store - Click the icon on the left that looks like two pieces of paper and select “1:24,000” for our standard map series. TopoView - Click on any of the round map scale indicators on the right side of the map. The National Map Viewer - Click on the Layer List icon at the top...
How are UTM coordinates measured on USGS topographic maps?
The UTM (Universal Transverse Mercator) coordinate system divides the world into sixty north-south zones, each 6 degrees of longitude wide. UTM zones are numbered consecutively beginning with Zone 1, which includes the westernmost point of Alaska, and progress eastward to Zone 19, which includes Maine. If UTM ticks are shown on a USGS topographic map, the zone is indicated in the credit legend in...
What is the State Plane Coordinate System? Can GPS provide coordinates in these values?
The State Plane Coordinate System (SPCS), which is only used in the United States, is a plane coordinate system (north-south and east-west lines are perpendicular) in which each individual state has between one to six zones, depending on the state's size and shape. This coordinate system’s high level of accuracy is achieved through the use of relatively small zones. The State Plane Coordinate...
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...
Topographic map symbols
What do maps show?
Finding Your Way with Map and Compass
Maps for America: cartographic products of the U.S. Geological Survey and others
Related Content
- FAQ
How do I find, download, or order topographic maps?
The U.S. Geological Survey (USGS) has been the primary civilian mapping agency of the United States since 1879. USGS topographic maps have been published at many scales, but 1:24,000 (also referred to as a 7.5-minute quadrangle) has been the standard topographic map scale since 1947. For Alaska the standard scale is 1:25,000. All dates and all scales of our topographic maps can be freely...
Are USGS topographic maps copyrighted?
All topographic maps produced by the U.S. Geological Survey (USGS) are in the public domain and are not copyrighted except for the following three cases that apply only to US Topo maps (produced 2009-present): Most maps in the period 2010-2016 contain commercially licensed road data (see note below). Orthoimages in Alaska are commercially licensed. Orthoimages in Hawaii were commercially licensed...
Can I still get the older topographic maps?
Yes. Topographic maps originally published as paper documents between 1884-2006 have been scanned and published as the USGS Historical Topographic Map Collection. Download our historical topographic maps and our more current US Topo maps (published 2009-present) free of charge using TopoView (GeoPDF, GeoTIFF, JPEG, and KMZ formats) or using the USGS Store’s Map Locator (GeoPDF format). Order paper...
What is a topographic map?
The distinctive characteristic of a topographic map is the use of elevation contour lines to show the shape of the Earth's surface. Elevation contours are imaginary lines connecting points having the same elevation on the surface of the land above or below a reference surface, which is usually mean sea level. Contours make it possible to show the height and shape of mountains, the depths of the...
Where can I find indexes of USGS topographic maps?
View map indexes on these interactive maps (you must zoom in to see the index lines and map names): Map Locator on the USGS Store - Click the icon on the left that looks like two pieces of paper and select “1:24,000” for our standard map series. TopoView - Click on any of the round map scale indicators on the right side of the map. The National Map Viewer - Click on the Layer List icon at the top...
How are UTM coordinates measured on USGS topographic maps?
The UTM (Universal Transverse Mercator) coordinate system divides the world into sixty north-south zones, each 6 degrees of longitude wide. UTM zones are numbered consecutively beginning with Zone 1, which includes the westernmost point of Alaska, and progress eastward to Zone 19, which includes Maine. If UTM ticks are shown on a USGS topographic map, the zone is indicated in the credit legend in...
What is the State Plane Coordinate System? Can GPS provide coordinates in these values?
The State Plane Coordinate System (SPCS), which is only used in the United States, is a plane coordinate system (north-south and east-west lines are perpendicular) in which each individual state has between one to six zones, depending on the state's size and shape. This coordinate system’s high level of accuracy is achieved through the use of relatively small zones. The State Plane Coordinate...
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...
- Multimedia
- Publications
Topographic map symbols
Interpreting the colored lines, areas, and other symbols is the first step in using topographic maps. Features are shown as points, lines, or areas, depending on their size and extent. For example, individual houses may be shown as small black squares. For larger buildings, the actual shapes are mapped. In densely built-up areas, most individual buildings are omitted and an area tint is shown. OnWhat do maps show?
The purpose of the teaching package is to help students understand and use maps. The U.S. Geological Survey (USGS) has provided the package as a service to educators so that more Americans will learn to understand the world of information on maps. Everything in the package teaches and reinforces geographic skills that are required in your curriculum.Finding Your Way with Map and Compass
A topographic map tells you where things are and how to get to them, whether you're hiking, biking, hunting, fishing, or just interested in the world around you. These maps describe the shape of the land. They define and locate natural and manmade features like woodlands, waterways, important buildings, and bridges. They show the distance between any two places, and they also show the direction frMaps for America: cartographic products of the U.S. Geological Survey and others
"Maps for America" was originally published in 1979 as a Centennial Volume commemorating the Geological Survey's hundred years of service (1879 - 1979) in the earth sciences. It was an eminently fitting Centennial Year publication, for, since its establishment, the Geological Survey has continuously carried on an extensive program of mapping to provide knowledge of the topography, geology, hydrolo - News