I'm pretty sure they were VHF in the 150 MHz band - I've still got my old Realistic 20 Channel Pro-2020 (and it still works fine) that I used to monitor them on. I had a couple of friends on the Jeep Posse and working as reserve deputies. They were able to purchase radios for use on patrols, and I'm almost positive they were around 155.xxx. Sorry I can't be more specific. If I trip onto an old list (I hope I threw them out long ago), I'll post. Sorry no info on radio models - I know the Posse and reserve used all sorts of radios based on what they could afford or find.
Prior to the county trunked radio system they're on now, they were mainly on UHF, with one VHF channel.
460.050 West 1
460.100 West Alt 2
460.150 East 3
460.200 Detectives 4
460.175 East Alt 5
460.075 Info 6
460.125 Phone Patch 7
159.090 Search 8 (Still in use)
159.390 Park Police (Park Police are now MCSO Mountain District 8)
There were a few other VHF channels being used by other county departments.