I'm not sure if they still do it this way, but the way they most of the State LE agencies USED to do it many years ago was by the Trooper's ID number, not by any kind of zone or sector number. So when you hear the dispatcher talking to a Trooper with an ID number of "one thousand (and somethin') you know he's probably not the most senior Trooper on the road, whereas some Trooper with an ID number of, say 500, has probably been on the street for 15 years.
The strange thing about that is that the ID numbers are "adjusted" by seniority periodically, like every year. So even if you did have an accurate list it would be obsolete the next time the ID's are adjusted. As the FHP's staffing decreases due to resignations, retirements, etc., those old ID numbers leave gaps in the ID number system. When they "adjust" the ID list, everyone's number moves lower on the list to fill in the gaps and new hires get the next sequential (higher) numbers. So, in theory, the Trooper with the lower ID number is the more senior Trooper. (for whatever that may be worth)
They may have a set bank of ID numbers reserved for different ranks, with the big bosses having the numbers below 50 or so... and Lt's, Sgt's, and other supervisors having blocks of numbers after that. But even in those blocks, I think they used to be based on seniority, with lower numbers being senior folks.
In the days before the Troopers had MDT's, I used to hear them come into service from home with their ID number and the dispatcher would tell them what "zone" they were working for that shift. But they would always use their radio ID number for their comm's...not their zone number.
Again, I'm not sure if they still do it that way but hope that helps answer your question. I believe that the Fish & Wildlife folks did it the same way.
