The Michigan Emergency Public Safety System (MEPSS), operates in simplex mode on 155.865 MHz. This is a statewide mutual aid/coordination frequency, used by all public safety first responders across the state. I believe that this is F-4 is most radios in Gratiot County. However, that may have changed that since they purchased new high-capacity two-way mobile and portable radios a few years ago.
73s
Ron