Sw Rma Tg?
Jim--
It's just a guess, But I think you may have come across a Southwest Regional Mutual Aid Talkgroup. I know they are out there. Each region of the state should have several RMA's we just can't hear them if we are not in that region.
I'm basing my guess on the type of traffic heard and the fact there is a pretty good break in talkgroup numbers between TG 46256 and the 48000's that are showing up on the Norman system.
But, I could be wrong
--fats2okc