Hammered Shield Lichen / Parmelia sulcata

I HOPE I have identified this lichen correctly. I have just visited friend Doug's photostream, as I knew I would, to look at his photos of this Lichen. When I picked out this photo months ago, I found I had already labelled it, so I think there must have been a reason why. If anyone happens to see this shot and could either confirm or correct the ID, that would be so much appreciated. Taken on 12th August 2010 in West Bragg Creek, Kananaskis.