Handbook of Texas Online - Current and historical information about Hildago County. - http://www.tsha.utexas.edu/handbook/online/articles/HH/hch14.html
Amphibians and Reptiles in Hildalgo County - Texas Cooperative Wildlife Collection list of species found in the county. - http://wfscnet.tamu.edu/tcwc/checklist/HIDAL108.HTM