Provincial Ambulance is 158.76 VHF with no tone (CSQ). It is a direct, simplex channel used mainly for STARS to contact ambulance or fire crews on the ground at a scene call. It is also available for ambulance services to communicate with one another. For example, BC Ambulance Service (BCAS) has Provincial in their radios and has been known to use it to contact Calgary EMS Dispatch when driving into town with a case that starts to go bad.
Just out of curiosity, what job was STARS on? I worked with them on Saturday night on a job in West Bragg Creek. It was a pretty insane wreck, minivan vs. trees, with one patient trapped in the car.