Chris Salgot owns a number of 800 MHz and UHF LTR repeaters throughout Arizona, a 461.XXXX LTR on Mt' Eldon in Flagstaff, a 451.XXXX MHz LTR on Mingus Mtn. Near Jerome, a 450MHz LTR on Glasford Hill at ~ 6100 feet in Prescott Valley and a 850 MHz LTR on the North West towers of Mt Union and this is probably the one that you are hearing.
The 800Mhz LTR repeater on Mt. Union is at a base height of ~7999 feet elevation give or take a few feet, 15 miles south of Prescott and from what i remember the tower is ~ 100 foot tall.
To listen to the traffic you need to create a new 800 MHz trunking system of type LTR.
This system uses 2 frequencies, the 1st frequency is 855.5125MHz with a LCN of 2 and the 2nd being 857.5375 MHz with an LCN of 7.
You should hear various users such as Waste management east with an talkgroup ID of 0-05-153 and
waste mangemnent west with a TGID of 1-07-153
Also the Chino valley schools used to use this system but I haven't heard them in some time but the TGID's were
1-07-062 ops a
1-07-065 ops b
1-07-067 school busses
1-07-083 security
There are also other users such as private utilty and delivery services Prescott transit and others which this sounds like you are hearing but I don't the other TGID's programmed in my radio at this time.
Enjoy listening to them, the repeaters put out a good strong signal from Mt. Union and can be heard out to a radius of 75 miles or greater from Union which is the Highest Peak in the Bradshaw range.
Mike
Prescott Az and Salem Ore., depending on what week of the month it is.
Oh yeah I almost forgot somewhere I believe that I may also have a file for those 900 MHz frequencies you listed but they are on my AZ PC and I'm on my Oregon Pc at this time.