The USGS has two options for acquiring 1:24,000-Scale (7.5-minute) Digital Elevation Model data.

1. The original DEM 7.5 minute tiled data available only in Spatial Data Transfer Standard (SDTS) form is available at no cost via downloads from the GeoComm International Corporation at http://gisdatadepot.com/dem and from MapMart.com at http://www.mapmart.com, and from Advanced Topographic Development and Images (ATDI) at http://www.atdi-us.com. (See disclaimer).

DISCLAIMER: The U.S. Geological Survey (USGS) has entered into an agreement with the GeoCommunity, MapMart.com, and ATDI, to serve updated, SDTS format, Digital Elevation Models (DEMs) through the GIS Data Depot at http://www.gisdatadepot.com and at MapMart.com at http://www.mapmart.com, and ATDI at http://www.atdi-us.com for no charge. The 7.5' SDTS DEM data are also available for purchase via premium (fast) download and on CD-ROM from GeoCommunity and for purchase on CD-ROM from MapMart.com.

The decision to provide SDTS DEMs through commercial vendors is consistent with the USGS goal of making more public domain data available at no charge while enabling the private sector to have a greater role in the distribution of USGS data. SDTS DEMs placed on media in response to customer orders will be sold by our partners at a price less than the USGS currently charges.

The GeoCommunity, MapMart.com, and ATDI will continue to receive SDTS versions of the DEMs as they are made available by the USGS.

If you have additional questions or comments, please contact us at sdts@usgs.gov. Please monitor the SDTS Home Page for further news and updates on this issue. http://mcmcweb.er.usgs.gov/sdts

2. The National Elevation Dataset (NED) is the result of the maturation of the USGS effort to provide 1:24,000-scale Digital Elevation Model (DEM) data for the conterminous U.S. and 1:63,360-scale DEM data for Alaska in a seamless form. Available data formats include ArcGrid, Floating Point, and BILS. For more information see (the NED Homepage), or go directly to the The National Map Seamless Server at (Seamless Store).

National Elevation Dataset (NED)

The National Elevation Dataset (NED) 1 Arc Second is a raster product assembled by the U.S. Geological Survey (USGS). NED is designed to provide National elevation data in a seamless form with a consistent datum, elevation unit, and projection. Data corrections are made in the NED assembly process to minimize, but not eliminate, artifacts, perform edge matching, and fill sliver areas of missing data. NED has a resolution of one arc-second (approximately 30 meters) for the conterminous United States, Hawaii, and Puerto Rico and a resolution of two arc-seconds for Alaska. This data can be downloaded at no charge from The National Map Seamless Server.

1:2,000,000 Digital Line Graphs (DLG) SDTS format only

Examples
DLG Standards
Review the 00README before downloading!
SDTS format only.
State
Graphics
SDTS DLGs require Master Data Dictionary
- SDTS Format Data Dictionaries: SDTS DLGs require the use of either the uncompressed SDTS Master Data Dictionary file as a single tar file for 1:2M, 100K, 1:24K or a series of uncompressed small files for 1:2M. 100K, 1:24K

1:100,000 Scale Digital Line Graphs (DLG)

File names changes
- Note: The file names have been changed to match the file naming structure from the production centers. A cross reference from the old naming convention to the new naming convention is available for optional (native) and SDTS formats.
Example
DLG Standards
Review the 00README for Native and the 00README.SDTS for SDTS before downloading data.
Alphabetical List
SDTS DLGs require Master Data Dictionary
- SDTS Format Data Dictionaries: SDTS DLGs require the use of either the uncompressed SDTS Master Data Dictionary file as a single tar file for 1:2M, 100K, 1:24K or a series of uncompressed small files for 1:2M. 100K, 1:24K

1:24,000 Scale Digital Line Graphs (DLG) SDTS Format Only

Example
DLG Standards
Review the 00README before downloading!
SDTS format only.
Alphabetical List
State
SDTS DLGs require Master Data Dictionary
- SDTS Format Data Dictionaries: SDTS DLGs require the use of either the uncompressed SDTS Master Data Dictionary file as a single tar file for 1:2M, 100K, 1:24K or a series of uncompressed small files for 1:2M. 100K, 1:24K

1:250,000 & 1:100,000 Scale Land Use Land Cover (LULC)

National Hydrography Dataset (NHD)

GTOPO30

Product Description
GTOPO30 download
Order GTOPO30 on DVD-- contact customer service (webmapping@usgs.gov or 1-800-252-4547)

HYDRO1K

HYDRO1k is a geographic database developed to provide comprehensive and consistent global coverage of topographically derived data sets, including streams, drainage basins and ancillary layers derived from the USGS' 30 arc-second digital elevation model of the world (GTOPO30). HYDRO1k provides a suite of geo-referenced data sets, both raster and vector, which will be of value for all users who need to organize, evaluate, or process hydrologic information on a continental scale.

1:250,000 Scale Digital Elevation Models (DEM)

1:24,000 Scale Digital Elevation Models (DEM) SDTS format only