Thanks for the kind words for my blogs! As for other resources, some good books are:
Edible and Useful Plants of Texas and the Southwest by Delena Tull.
Beacomber's Guide to Gulf Coast Marine Life (covers Florida, Alabama, Mississippi, Louisiana, & Texas)
Animal Tracks of Texas by Sheldon & Hartson

You might also track down information on Caddo Indians. They lived across Arkansas, Louisiana, and East Texas. There's a number of books about them available, but I haven't look at any and can't recommend a particular one.

-Blast