ArcGIS Online
USA Elevation
Globe Service Name: USGS_Elevation_US
ArcGIS Desktop/Explorer URL: http://services.arcgisonline.com/arcgis/services
ArcGIS Server Web ADF URL: http://server.arcgisonline.com/arcgis/services
View Service In: ArcGlobe ArcGIS Explorer
Description:

This globe presents elevation for the contiguous United States at a resolution of about 30 meters. The data is from the National Elevation Dataset (NED) produced by the United States Geological Survey (USGS). NED is designed to provide national elevation data in a seamless form with a consistent datum, elevation unit, and projection. Vertical units are measured in meters.

Attribution: Source: USGS
Usage Restrictions: See license summary
Extent: Maximum Longitude: Approx. -66
Maximum Latitude: Approx. 49
Minimum Longitude: Approx. -125
Minimum Latitude: Approx. 24
Publisher and Place: ESRI, Redlands, California, USA
Publication Date: December 2007
Update Frequency: As needed