Texas DOT publishes a useful brochure "Texas Public Campgrounds" that lists all the non-private campgrounds in the state including city, county, state and federal!
The only problem I have with it is that the campgrounds are listed alphabetically by the name of the nearest municipality (which can be a tiny town) so it's very difficult to use it to figure out "OK, we're going to Clifton, what public campgrounds are nearby or on the way?" One of my retirement projects is gonna be to index this brochure by lat & long so that I can load the campgrounds into mapping software...
It can be downloaded here:
http://ftp.dot.state.tx.us/pub/txdot...ampgrounds.pdf