All based on the rule of capture from english common law. The rule of capture is now subject to state regulation under certain situations to avoid waste and protect correlative rights. The rule of capture came from the taking of wild animals at common law - you did not own them as they could run away and leave your property but you had the right to capture (kill) them while on your land. Compare to water or oil/gas etc. If you can capture it on your land you own it subject to regulation for the protection of correlative rights and to avoid waste. Your neighbor's protection is his right to capture his own water etc. also subject to regulation.