Being March, I must assume he has lost alot of condition. I would say that deer is 2.5 to 3.5 really hard to tell. He is not sway backed, and doesn't have the belly of an older deer. he doesn't appear to have the big Roman Nose of an older deer either, although this is not the best photo for that. however, he has retained alot of weight through the winter, leading me to lean more toward the 3.5 age class.
Of course I may be totally wrong.