Not every state treats navigable waterways this way. In my state (Nebraska) it is enforced that the landowner owns the bank and the river bed, the public has the water. If you drop anchor or step foot on either without permission you could be cited for trespassing. The exception is if you are portaging around an obstacle. From what I have read if this were to get challenged in court, as has happened in other states, statutes might be changed to align with federal precedent. The case would have to be argued up to that point first, however. Long and short of it, every state may treat the issue differently, so know your state laws unless you want to be the one to argue a case to the state Supreme Court.