Frequently Asked Questions

Mapping, Remote Sensing, and Geospatial Data

The USGS provides the mapping and digital geospatial foundation for the Nation.

Filter Total Items: 262
USGS map showing the intensity of potential earthquake ground shaking that has a 2% chance of occurring in 50 years. Click image
The National Map uses the same Web Mercator-based tiling scheme as Google/Bing Maps because it has been widely adopted. For example, ArcGIS Online moved to this tiling scheme as well. With a unified tiling scheme among major web mapping services, it is easier to mash-up data between them and is now customary in web maps designed for mass...
Mercator the Man
In addition to the WGS84 Web Mercator Auxiliary Sphere projection (EPSG:102100), TNM services support commonly used spatial coordinate reference systems, such as CRS:84 and EPSG:3785, 3857, 4267, 4269, 4326, 54004, 54008, 102113, and 900913. TNM services also support Alaska and North Pole projections/coordinate systems, such as EPSG:3338, 3571,...
In the past, each USGS topographic map typically required 3 individual lithographic stones for printing, one for each color show
The National Map services are supported in: 2D Viewers - any major viewer using the Web Mercator projection, such as Bing Maps or Google Maps. 3D Viewers - Google Earth, NASA WorldWind, or ArcExplorer. GIS Application Viewers - ArcMap, Gaia, or Global Mapper.
The National Map Hydrography Viewer
Yes, The National Map supports services to be consumed in multiple viewers or Application Program Interfaces (APIs), such as your own or favorite popular viewer, or in GIS applications, such as ArcMap.
Image: USGS Topographer at Work
Did you try adding TNM services through ArcCatalog first? Is the word "rest" in the .../arcgis/rest/services URL? Recall that you do not need the "rest/" portion if using ArcGIS 10.0 or earlier versions, so this may be the problem if you copy and paste the URL from ArcCatalog. Can you access the service via a web page? Add "rest" back into the URL...
Image: USGS Cartographer at Work
Start at The National Map-Service Endpoints. Click on the WMS link for the selected service (verify that your pop-up blocker is turned off). Highlight the WMS URL from the address bar of the Web browser. Copy the base part of the WMS URL (everything to the left of the question mark). For example, Geographic Names WMS URL https://services....
The National Map
Use ArcCatalog to initially add a TNM REST service in ArcGIS. Copy a URL from The National Map-Service Endpoints. If using ArcGIS 10.0 (or earlier versions), remove the "rest/" portion from the URL. Here is an abbreviated list to set up quickly: Base Map Services: Theme Overlay Services: https...
3D Lidar Point Cloud of the United States Capitol Building
There are two methods:   Click on "View In: Google Earth" at the top of an individual REST service endpoint accessed through The National Map-Service Endpoints. Add "/kml/mapImage.kmz" to a REST service endpoint, such as
Navigate to a specific base map or theme overlay layer in The National Map-Service Endpoints and call one of the URLs. Click on the "WMS" link. The service call will look like [Base URL] /arcgis/services/xxx/MapServer/WmsServer?, where "xxx" is the service name, such as "nhd". Notice that the "/rest" portion is not in the service call. Add the...
Visit our API Examples Demos Web page for TNM services being used in other Application Program Interfaces (APIs), such as Leaflet, OpenLayers 2, Google Earth, and OpenLayers 3 Mobile. Other examples include usage of the Elevation Point Query Service (EPQS) and an Arctic Spatial Data Infrastructure (SDI) viewer.
 A 3DEP Image of Alaska's Denali Mountain
TNM services are designed to be consumed as Web Map Service (WMS), Keyhole Markup Language (KML), or ArcGIS Server REST API calls.
Screen shot of streams near the Dillon Reservoir, Frisco, CO on imagery basemap
A complete list of service URLs is at The National Map-Service Endpoints, which contains available REST, WMS, WMTS (cached base maps only), WFS, WCS, and other service links. You can also browse to any of the following links to view services directly: Base Map Services Theme Overlay Services...