Ryan,
The hunt, to my knowledge has always been in either Schulenburg or Hallettsville, and maybe once in Columbus early on. I know a couple years ago, there was discussion about moving it to a more central location. Not sure if that's still in the cards or not.
In the spring, you will find several Hog Dogging contests. Cuero, Pearsall, Hallettsville, and Buffalo/Fairfield seem to be the four largest.
Thanks Circle C, I appreciate it buddy! Have a good one!