I'd say a short 3yr old or a long 2yr old (i.e. 2.5-3.5)... But then again, I'm not as familiar with high north whitetails as I am with midwesterns...
Despite what the "all knowing" Mr. Deerhunter says, yes, you can fairly accurately estimate the age of a deer by the external appearance. Still a narrow muzzle/snout still developing muscles in the shoulder and hind quarters, narrow brow, not much white around the muzzle, youth in his knees, not much depth or width in his chest, high elasticity in his gut (looks like he has a beer gut, cuz his ab muscles are still holding paunch tight, but they're flexible enough to let his full belly drop a bit)... All that points to a fairly young buck, but at his size, he's no baby...
Great rack for his size and age too... If the pressure is on, I'd take him out this year, if he's hidden away somewhere that nobody else hunts on and there's no other reason he'd venture elsewhere, then I'd give him another couple years (assumes you don't have other bucks his size or larger in the area that might push him off the territory, and that his harem-when he finds one-doesn't lure him elsewhere)