This is the law in PA: Chapter 23: (2) Individuals who find and retain for their own use any deer or elk antler which is shed through natural causes. This paragraph shall not be construed to permit any individual possessing a shed antler to sell, barter or trade or to offer to sell, barter or trade any shed antler.
Antlers laying in the woods aren't wasted, they are used as a source of calcium by wildlife. Anyone who has spent time in the woods probably has seen antlers that were showing signs of being eaten.