The USGS US Topo Availability service from The National Map consists of footprints where US Topo products are currently available. Various green tints are used to reflect the year in which US Topo map products have been published. The service is updated daily and contains the same data used in footprints in the Map Locator & Downloader application program interface used in the USGS Store (http://store.usgs.gov). In addition to access through The National Map download client (http://viewer.nationalmap.gov/basic), US Topo products and other USGS publications are available through the USGS Store. For additional information, go to http://nationalmap.gov/ustopo.

The USGS Map Indices service from The National Map (TNM) consists of 1x1 Degree, 30x60 Minute (100K), 15 Minute (63K), 7.5 Minute (24K), and 3.75 Minute grid polygons used in The National Map viewer for reference and to download data. At 1:24,000-scale (24K), the standard map size is 7.5 minutes of latitude by 7.5 minutes of longitude. At 1:100,000-scale (100K), the standard map size is 30 minutes of latitude by 60 minutes of longitude. The National Map viewer allows free download of public domain USGS map indices data in Esri File Geodatabase format.

The USGS Map Indices service from The National Map (TNM) consists of 1x1 Degree, 30x60 Minute (100K), 15 Minute (63K), 7.5 Minute (24K), and 3.75 Minute grid polygons used in The National Map viewer for reference and to download data. At 1:24,000-scale (24K), the standard map size is 7.5 minutes of latitude by 7.5 minutes of longitude. At 1:100,000-scale (100K), the standard map size is 30 minutes of latitude by 60 minutes of longitude. The National Map viewer allows free download of public domain USGS map indices data in Esri File Geodatabase format.