- Butterflies of Ellis County, Texas - Information about and pictures of all the known species of butterflies in the county.
- Ellis County Report: Pollution Locator - Map of the polluting sources, air quality ranking, and other pertinent environmental data for Ellis County, TX.
- Ellis County Watershed Template - From the Environmental Protection Agency; explores America's water resources with an emphasis on the quality of our Nation's water and features powerful searching, mapping, database querying, and informative hot links.