Have you guys up in the Duluth and Iron Range area determines any official channels names? For example, is there anything that is:
-----SU LAW 1 or SU L MAIN 1
Is they are referring on the air to "LAW 4", then there must be a LAW 1, LAW 2, and LAW 3. That is not to say that every county is going to use the exact same names, but I think the patterns are pretty similar around the state.
There has been some previous discussion of talkgroup names here
http://forums.radioreference.com/minnesota-radio-discussion-forum/248313-names-new-nobles-tgs.html I might have guessed that Saint Louis County would be SL or ST, but it looks like SL is STeele and ST is STearns. So in the case of Duluth Police, a talkgroup for them might be SU DU TAC. Also, a Duluth Fire talkgroup might be SU DU OPS 2.