Hays Trinity Groundwater Conservation District
- Works to conserve, preserve, recharge and prevent waste of groundwater within western Hays County. Information on board meetings, rules, and well monitoring, with downloadable forms.
- http://www.haysgroundwater.com

Amphibians and Reptiles in Hays County
- Texas Cooperative Wildlife Collection list of species found in the county.
- http://wfscnet.tamu.edu/tcwc/checklist/HAYS105.HTM