As other's said, you can't do much in a state park besides picking up surface things. And actually if you are picking up bottles off the ground, you are doing the park a great favor by helping to remove debris. They certainly would prefer not to have glass laying around in the woods. But yeah, you can't do any digging. Those A/B bottles are really common. I see them all the time. They display well. But eventually you'll find much better ones to replace them on your shelf. I'm running out of room to display all my nice bottles.