Dennis,
There is really not that much activity on the system. The Sheriff's Office and Park Police are the only police agencies dispatched on it and the Prosecutor's Office runs 100% encryption. Both the SO and PP are dispatched on TG 32784. The dispatch center is known as "Comm 2." The 91 series cars are the Park Police. Their Tac channel, referred to as Channel 4 is TG 33072.
Most departments that are dispatched by Morris County are still on low band. Rumor is they may go to the trunked system and use the MGLE talkgroups, but that is not what the system was designed for. The system was designed for interop communications for all agencies in Morris County. One such example is Morris County Airport. All fire agencies will initially be dispatched on their respective VHF and UHF channels, but will use MIRS-1 and then switch to a interop TG specific to fire to coordinated activities. I haven't officially confirmed this as most traffic is repeated over UHF or VHF, so by montiring that you pretty much get an idea of what's going on.
You will occasionally hear police bases calling each other on MIRS-1 (TG 33328), but everyone seems to still use SPEN-1 since other agencies like NJSP, Feds, etc don't monitor the trunked system.