A database of dissertations and theses from around the world, including links to full text for dissertations written since 1997 and some fulltext coverage for older works. If you're unable to access the full text of a document, please refer to the instructions to log in to ProQuest.
Search for aerial imagery, AVHRR, commercial imagery, digital elevation, Landsat, LiDAR, MODIS, Radar and more earth science data from the USGS and NASA. You'll need to register for a free account in order to download data. See this quick guide to get started.
An authoritative source for information on more than 70,000 plants, animals, and ecosystems of the United States and Canada. Explorer includes particularly in-depth coverage for rare and endangered species.
Database of U.S. Environmental Protection Agency activities and data relevant to wastes, pollution, toxics, etc. that affect air, water, and land anywhere in the United States. Maps can be generated from the data.