Reddit mentions of Red River Shootout Texas vs Oklahoma 1997 Texas Football Program

I was curious about this so I did some digging. I definitely remembered it being called the shootout when I was a teen in the late 90s.

It possibly began in 1995.
Here is an article from 1996 that mentions that is the 2nd year that it is called the Dr Pepper Red River Shootout. Unclear if it was just called the Red River Shootout before that.

Here is a program from 1997 that you can buy that illustrates the name, and similar items can be found on ebay.

Similarly, programs from the late 80s can be found on ebay that do NOT call it the shootout. There seems to be a gap in available programs from the early 90s.

Here is what I find most interesting:
You can search old newspaper archives for the phrase, and it seems the Red River Shootout name was invented in 1988 for a golf tournament between Texas, OU, and some other schools. The "shootout" bit is a specific style of golf tournament starting with 19 players, where 1 player is eliminated each hole, until you crown a champion after the 18th hole.

I think someone just thought the name sounded cool (despite the specific meaning of shootout in golf), and lifted it from the golf tourney to be used for the football game.