What bird is this?

During the Summer, I went to Calgary and while there I took the opportunity to visit Lake Louise, which is just past Banff and not a long trip from Calgary. I left in the morning and checked into a local hotel. Asking at the reception desk for directions to the lake, I was told to make sure to go early in the morning because it gets very crowded. They were right! Had trouble finding a parking place, seemed everybody had the same idea. So, walked around the lake with its classic view of the Chateau Lake Louise at the end of it, got back to the car, lay back in the seat and there was a "thump" noise on the external mirror. There was this bird sitting looking at me - camera in its case of course, but I did manage to get it out, focus and take one shot before it flew away. What was it? Woodpecker? It was large, but I have no idea. If any of you bird watchers know, I would be interested to see what it was (make a comment).