Around here (southern IL) I hear them mainly use the state police frequencies in use in the district they are in. If you see on the license plates on their trucks, it says something like F5-31, but over the radio, it is read 5 Frank 31. In case you also here a call sign like this, but read with a John instead of Frank, those are SOS units, but they seem to all work of the same channels. You might look on the Starcom21 trucking page, to see if they have their own talk group. But I hear them a lot still using High band to run 27/28 through the local ISP post.
Steven
