Here's another: FRONTIER TRUST
These guys played in St. Louis a couple of times back in the '90s and were fan-fucking-tastic. It was more than just "cowpunk"... more like TRACTOR PUNK. I can't find any videos on YouBoob (a shame), but if I were you, I'd hunt down their "Speed Nebraska" LP... click the link below:
http://www.speednebraska.com/independent_bands/frontier_trust.php
Supposedly you can get a free download here, but I can't get the page to come up:
http://www.thebandbrokeup.com/2011/02/05/frontier-trust-speed-nebraska/
Amazon has it, though:
http://www.amazon.com/Speed-Nebraska/dp/B003DZEK2S/ref=tmm_msc_title_0