Geez guys. This is about as enforceable as doing 72 in a 65 at 5:10 pm. Do what you think is the right thing to do. For me, I call the owner two times. If they don't come and get it, it's mine.
That's why it's ridiculous that the state would have a say in the matter at all. Seriously, anyone who calls the cops over a golf disc is a bigger d-bag than those who don't try to turn in the lost discs they find.