Hey robertmac. When I've heard dispatch (Red Deer 911 PSAP) talking to the agencies they dispatch, they always advise the fire units to "switch to provincial EMS simplex to speak with STARS". I'm not sure what other frequencies STARS may have access to (or should be using), but through the course of former employment, I did not see anything in the FD radios other than what's already known/posted on here. [Disclaimer: All frequencies being discussed here are in the TAFL/public disclosure]
Once you go north of Mountain View County, all fire agencies on #2 are VHF, with the exception of Red Deer City, who are on AFRRCS with clear talkgroups. I've posted VHF frequencies in another thread, but here are some of the systems going up to Edmonton. All agencies are dispatched by Red Deer 911, with the exception of Maskwacis, which has their own EMS/Fire dispatcher on the reserve:
Red Deer County Fire: VHF analog repeaters
Blackfalds Fire (Lacombe Co.): VHF analog repeater
Lacombe County [inc. Lacombe City]: 7 linked VHF analog repeaters
Ponoka County East/West: VHF DMR, Two IP Site Connect repeaters, clear
Wetaskiwin County: VHF Analog repeater
Maskwacis (formerly Hobema), backup to Wetaskiwin County FD: VHF Capacity Plus DMR, encrypted
Leduc County: AFRRCS, clear
All of these agencies (except Leduc?) have VHF provincial EMS 158.76 in their radios. I've monitored Red Deer County, Blackfalds, Lacombe and Ponoka speaking with STARS on this frequency. I'm sure Maskwacis has it, too.
Bottom line: If doing a run up the deuce, and you want to listen for crashes/closures, be sure to program your scanner/ham rig/pro radio up for these agencies. From Mountain View to Leduc, it's all VHF. Pretty quiet most of the time as these are all volunteer departments, but when it's busy, there's plenty to hear. Mutual aid programming (neighbouring counties have each other's VHF repeaters) is also done quite well. The FFs are very familiar with how to work their radios. I'm impressed. No mouth breathing.
Unfortunately, these VHF agencies cannot communicate directly with AHS. All info is relayed to RD 911, which does suck in terms of latency/convenience/common sense.