Butterflies of Seneca County
- Presents photos and species accounts of butterflies found within the county.
- http://www.butterfliesandmoths.org/map?dc=5478&_dcc=1&si=36

Seneca County Environmental Data
- Index to program areas, educational information, newsletters and events available through Ohio State University Extension.
- http://seneca.osu.edu/

Seneca County Ground-Water Resources
- Factsheet providing information on ground-water resources in the county.
- http://ohioline.osu.edu/aex-fact/0490_74.html

Water Resources of Seneca County
- Factsheet providing information on water resources and drinking-water quality in the county.
- http://ohioline.osu.edu/aex-fact/0480_74.html