The Crustal Dynamics Data Information System (CDDIS) supports data archiving and distribution activities for the space geodesy and geodynamics community. The main objectives of the system are to store space geodesy and...

Ecoregions denote areas of general similarity in ecosystems and in the type, quality, and quantity of environmental resources. They are designed to serve as a spatial framework for the research, assessment, management,...

This portal provides access to resources on geologic mapping, and to sources of geologic maps. There is an introduction to geologic mapping, which summarizes its principles and practices, and a history of United States...

The University of Arkansas Library offers the Guide to Mostly On-Line and Mostly Free US Geospatial and Attribute Data Web site. The main page contains a list of every state and related links to available geospatial and...

With the exponential growth in geographic information systems (GIS) across the United States, there are a number of organizations with an interest in coordinating a variety of activities around the sustained growth and...