I've had several people asking me about getting a TX fishing license for Marin Creek, here is the website: http://tpwd.texas.gov/business/licenses/online_sales/
Over 65, you need a Louisiana resident fishing license or lifetime license. Disabled veterans can get a free license online. Under 17, you only need an ID to prove your age.
Non-resident annual freshwater license = $53
Non-resident 1 day all water = $16 (must be for Jan. 14th)
Convenience fee (to pay online) = $5