afish, again, the landowner's argument is that the Montana case in 2012 opined by the U.S. federal supreme court negates the 1999 case you are discussing.
I don't know if there's been another case regarding the Lehigh post 2012. The landowner might have a point. I'm not a lawyer and there are a lot of details to decipher. i.e. yes, I think per the latest case the reasoning behind the 1999 decision has probably been overturned. Because the court in 99 Lehigh case said that a stream navigable in part is navigable in whole, and refused to take a piecemeal approach to the question of navigability. The Supreme Court of the U.S. in 2012 said that this approach is not correct, and that streams/rivers must be examined on a section by section basis.
That said, it doesn't make the landowner right on a number of points.
1. Precedence. The 2012 case said was a specific Montana case. If there hasn't been a subsequent case in PA, then I think the 99 decision still holds until further notice. In 99 the decision said that the entire river is navigable. So that's the status quo. I think this landowner may have a legit argument and probably could get the court to re-examine this particular section. And upon review, PA courts would have to abide by the Federal section by section guidelines stemming from the 2012 case. Still, though, a court has to actually review the section in question, and rule in favor of the landowner, before there's any change of the status quo? Has that happened? i.e. has there been any cases post 2012 regarding this section of the Lehigh? ?
2. Even if the landowner succeeded in getting it back in court to re-examine his section, and even if this particular stretch deemed not navigable, and the stream bed given back to the landowner. Even if all that happened, I'm still not sure whether he has the right to post it. I'm not sure. Not saying he does or doesn't. Just that it's not as simple as yes navigable or no navigable. The river as a whole would still be considered navigable, even if that section in particular is not. The 2012 Supreme Court opinion, to my non-legal mind, seems to separate navigability for the sake of determining monetary ownership (must be examined piecemeal for taxes, rent payments, mineral rights, etc) and navigability for the sake of public recreation rights. i.e. that section could be non-navigable and thus privately owned, while still part of a greater, navigable waterway where the entire length grants public rights.