Michigan's Public Safety Communications System (MPSCS) Zone Number
From The RadioReference Wiki
1 South Central Lower Peninsula
2 Southeast Lower Peninsula
3 Southwest and North Central Lower Peninsula
4 Northern Lower Peninsula
5 Upper Peninsula
6 Upper Peninsula
7 Wayne County
8 Unknown
9 Extra Zone for additional Radio ID's
1041 Kent County
1061 Muskegon County
1141 Grand Rapids City
Michigan's Public Safety Communications System (MPSCS) Radio ID Structure