Here is a link to an article in the Port Arthur News dealing with big gar in Texas' Trinity River.
In the article, Chester Moore, Jr. documents his interview with Jeremy Wade the host of the Animal Planet show River Monsters. The show documents Wade's search for giant fresh water fish around the world. One of the first shows was about the large gar in the Trinity River of Texas. Wade had this to say about the alligator gar of the Lone Star State, "Each of the species is unique in its own way so it's kind of hard to compare but the alligator garfish definitely ranks high in among the 'river monsters' out there."
Check out the entire article. It is a good read. Also, note this is part one of an interview with Jeremy Wade. Make sure and check back soon for part two of Moore's interview.