First, Welcome to Maine in advance. You will be driving right through Bangor on your trip. I wish you a safe and pleasent trip.
You might have already looked at this but the Aroostook Fire Protection District guys have put together a nice feed
here with some frequencies and a little help with how they go together.
I generally have to dig through FCC docs and have been searching for the right tones around my area. Thats whan I found the
RFWIZ.com site. They might have a few things the others don't.
Then again you might have already tapped these.
Not sure what you want to hear but put LifeFlight in. They have a tower on Mt. Chase and will switch to that if flying up there.
453.650 PL 103.5
Crown Ambulance is the private service up there that covers alot of ground too.
Hope that gives you something to chew on.