Umm FYI size in the chow standard is not that important I have seen some chows that top 165lbs. And he does not look that big, I see chow, maybe some shepherd, or collie, but he is defiantly not a wolf cross, IMO. And if he is bigger than a chow then he is not coyote either.
I think he's St. Bernard for sure, crossed with possibly a Great Pyrenese or a Bernese Mountain dog. He's tri-coloured, which could mean he's got a tri in his background, or he's tri because of the mixture!