Dryas drummondii
The most common Dryas in Alberta, and very widespread, from the foothills (I think it follows some river valleys even farther down out of the actual hills) to alpine areas (Lori can better comment on its presence in real alpine places, though I know it's common in places such as at the foot of the Athabasca Glacier, a site with colonising and alpine flora, though technically it's below the treeline).