Bird on the roof

I have had a quick look to try and ID this bird, swift, swallow, house Martin, ( I always get confused) or something else as I am in the Canadian Rockies. There was a group of them on the roof tops chattering away 19 to the dozen.
Thank you for the stars and favs for my Lake Louise flower picture. Time is pressing at the moment. We are going on a 4 hour slow boat trip this afternoon with the other grandparents and the grandsons' cousins, not sure what we are letting ourselves in for as it's hot again.