How often are The National Map's composite base maps and dynamic service overlays updated?
Composite base maps are recached about once a year. Although data in dynamic service overlays are ideally updated quarterly, it can sometimes take up to six months. Please note that there will be times when composite base maps and dynamic service overlays are not in synchronization because of a difference in refresh cycles.
Subscribe to the National Map Simple Notifcation Service (SNS) to stay in touch with changes to The National Map products.
Related Content
What is the difference between tiled and dynamic services?
What are the base map services (or URLs) used in The National Map?
Where can I find a list of URLs for The National Map services?
The National Map—New data delivery homepage, advanced viewer, lidar visualization
As one of the cornerstones of the U.S. Geological Survey’s (USGS) National Geospatial Program, The National Map is a collaborative effort among the USGS and other Federal, State, and local partners to improve and deliver topographic information for the Nation. The National Map is featuring direct links to new and improved GIS data access utilities...
The 3D Elevation Program—Supporting California's Economy
IntroductionCalifornia faces unprecedented challenges presented by shifting weather patterns that are defining a “new normal.” The result has been extreme weather events, prolonged drought, flooding, and debris flows. These conditions drive severe tree mortality, increase wildfire occurrence and intensity, reduce water availability, and hasten...
Ostergren, Carol L.; Decker, Drew; Carswell,, William J.
US Topo—Topographic maps for the Nation
Building on the success of 125 years of mapping, the U.S. Geological Survey created US Topo, a georeferenced digital map produced from The National Map data. US Topo maps are designed to be used like the traditional 7.5-minute quadrangle paper topographic maps for which the U.S. Geological Survey is so well known. However, in contrast to paper-...
Fishburn, Kristin A.; Carswell, William J.
Map projections
A map projection is used to portray all or part of the round Earth on a flat surface. This cannot be done without some distortion. Every projection has its own set of advantages and disadvantages. There is no "best" projection. The mapmaker must select the one best suited to the needs, reducing distortion of the most important features. Mapmakers...
USGS Digital Elevation Models (DEM) Switching to New Distribution Format
In support of ongoing efforts to provide efficient, cloud ready, open data formats, the U.S. Geological Survey National Geospatial Program is announcing plans to migrate its 3D Elevation Program (3DEP) Digital Elevation Models (DEM) to a new data delivery format called Cloud Optimized Geotiff (COG) during the first half of fiscal year 2020.
USGS 3DEP Lidar Point Cloud Now Available as Amazon Public Dataset
The USGS 3D Elevation Program (3DEP) is excited to announce the availability of a new way to access and process lidar point cloud data from the 3DEP repository.
USGS Topo Base Map Refreshed and Other Updates
The “USGS Topo Base Map” service named “USGS Topo” has been refreshed with new data and design changes. In addition, several of the “Data Availability”, or “Data Index” services have new cloud hosted URLs.
Mapping Public Lands in the United States
The Protected Areas Database of the United States (PAD-US) is the official inventory of public parks and other protected areas in all U.S. states and territories.
Using US Topo and Historic Topo Maps on your Mobile Device
Lesson 6a: Using USGS US Topo and Historic Topographic Maps on your Mobile Device - This video demonstrates how to download and use US Topo and Historic Topographic maps on a mobile device.
Please note that some of our URLs in the video have changed. All URLs beginning with 'viewer.nationalmap.gov/...' have been updated to 'apps.nationalmap.gov/...'. These URLs
Elevation
The National Elevation Dataset (NED) is the primary elevation data product produced and distributed by the USGS National 3D Elevation Program (3DEP). The NED provides seamless raster elevation data of the conterminous United States, Alaska, Hawaii, and the island territories. The NED is derived from diverse source data sets that are processed to a specification with a
PubTalk 11/2004 — From Plane Tables to Pixels
The Revolution in Mapping at the U.S. Geological Survey
by Susan P. Benjamin, Research Geographer
- Mapping the United States in the 19th century was arduous, dangerous work; flash floods, bears, and bandits were just a few hazards
- By the mid-20th century, aerial photography, photogrammetry, and stereophoto pairs, allowed
Updated 2015 version of Tupelo, Mississippi US Topo quadrangle with orthoimage turned on
Updated 2015 version of Tupelo, Mississippi US Topo quadrangle with orthoimage turned on. (1:24,000 scale).