Whitetail Deer in this part of the country generally begin losing their horns around February - March.  After horns have dropped, shed hunting is pretty popular around here.  Great places to look for sheds are fence lines.  Often when jumping a fence a buck will lose one, if not both horns during the jolting to his head.  It is not uncommon to find one horn on one side of the fence and the other across the fence.  When a buck has something distinct to his antlers, this is a great way to track his growth from year to year if you can find his sheds throughout his lifetime.