RE: I think they got poached.
probably a number of things....
change in food source
hunting pressure (bucks that size draw a CROWD...i dont care HOW posted a place is...i can almost guarentee that its being hunted without your knowledge....ive watched people get dropped off so they can sneak into areas...
spotting pressure...i see it EVERY year...deer get SICK of being spotted, guys driving into the fields for a better view, getting out with handheld spotlights etc etc....deer aint dumb...
and probably more factors
could been poached...but they could also still be there and go unnoticed...