Traffic on the high sites is hit and miss because it depends on users to be affiliated with them. If there are no users of particular talkgroups affiliated, then it does not transmit the talkgroups.
Here are the high sites I can receive, and talkgroups they *sometime* carry:
South Mountain – Chandler PD A02 2498, Maricopa PD 2599, PPD South A4 2996/B4 2980, Fire K deck
Sacaton – Fire K1, K8, Maricopa PD 2599
Thompson Peak – Scottsdale PD2 3402, MCCC 4555/4557, Fire K deck
There are likely also public works talkgroups on these sites, but I have these all avoided as I don't listen to garbage trucks, water works, etc.
If you rely on the high sites to receive these channels, you will frequently be missing activity. As an example, as I type this post, Chandler PD, PPD South, and Fire K Decks are NOT being carried currently on South Mountain. I am hearing them on Simulcast C, but not South Mountain. I am only hearing Maricopa PD 2599 on South Mountain.
Hopefully other listeners can provide some info on the North & West sites as I cannot receive them as I have this big mountain in my way.