If you see a nice fly rod and reel resting against a tree at a popular access point and there is no other car close by, just leave it there. Eventually the owner will realize where he left it and he will come back to get it. If you find a rod and reel underwater in a river, take it to the closest tackle shop and tell them where you found it. Also write down the manufacturer and the serial number on the rod. Then call the manufacturer, they may have the owners name and address on record.