Haha, I totally recognize the facility in your pics, Rocky is one of my favorites!
Your guy is gorgeous, he actually looks VERY similar in both build and color/markings to a friend's horse who also events around here, she has Shire/TB mare. So that would be my guess. She'll be at most of the events, she rides Prelim and the horse's name is Wellington Wren if you want to keep an eye out. Not sure where she got her mare from, can't remember offhand, but to me they do look quite similar! There's actually a few pics of the mare up on the Alberta Horse Trials website home page, on the slide show on the top right, she's the big mealy bay with a stripe down her face if you want to check it out.