People vs Emmert (1979) is the case, and since at one point they stepped on the riverbed in a privately owned section, it is not a clear statement on the law.
There are some AG and Exec Director of Natural Resources issued opinions, but they also are not the final word on the issue. Basically, until a court issues a direct ruling, things will remain fuzzy. The problem is, once the supreme court has spoken, it's over. And no one, including American Whitewater, is totally confident in that final result, which is why they have been working on this incrementally.
I suggest touching base with American Whitewater before you do this. This is very much like the Sportmen's Paradise