Politics aside, easements and division of parcels is done all the time to protect the public's interest.  The DEC needed only to purchase an area to provide parking and a trail to the river as well as a curtilage area from the river bed back some fifty or one hundred feet.  Think of all the money the State wasted on the purchase of the Portly Angler, more than enough to purchase the school property. 

I  only think that there may be a precedent here because of what happened on Oak Orchard, where a couple of enterprising anglers (who some of us knew well from their days guiding on the SR) angered the local fishing community by basically doing exactly what this business is doing, and then got told that the bottom in the Oak was not part of the riparian property.  There is a difference between a riparian right, and a clear title to the bed and bottom.  And this may be another one where it will have to be resolved in court when the new " owners" prosecute someone for trespass on what may not be theirs to claim. Only time, and maybe discussion with someone who should know as steward of the public fishery, like Fran Verdoliva, will tell.
 
L13

Seems to me I saw a property LINE on that map- irregardless of the meanderings of the  SR it would seem a line is a line.
 But then laws all too frequently defy common sense.

 
This is straight from the Oswego county tax map viewer.......
 

Im pulling plugs through there just like ive done the last 14 years! That looks like a lot of property from the view, they should put a par 3 golf course around the property and a 3d bow course through the woods, gonna pay taxs might as well use the land.

That property line does not go to the rivers edge in a few spots,how are they going to determine "their" exclusive fishing?

If the aerial map that Clint posted is accurate only about a third of the property reaches into the river.  It looks as if it will be difficult to try and enforce trespassing laws particularly below the thumb in the center of the property.    

Here is the link for he Oswego county tax site.
On the Pin property there is a picture very similar to the one I posted
On the view tax map it is  PDF and the lines are the same, but you cannot see the river, but the lines are the same.
  http://rptsweb.oswegocoun...y=08801800020020000000
Only one small chunk actually goes out into the river.  
I notice in the facebook posts he does say they own to the middle, but always says the "Bank"   is for guests.
 
I would guess  if they start trying to kick boats out, the guides will get PO's and take them to court..................
 
I just posted this picture on their site  right after where they stated they owned to the middle and asked if this was an accurate rendering of the lines.   
2 to 1 it gets pulled.................

I thought in the Joke Orchard case eventually the owner had a new survey done and found he own that property actually  owned more of the river than he was originally posting.
 Didn't the state cave and pay him to allow access, which is what he asked for from the start.?

 
With all those large trees in bloom along the line its impossible to  see where the waters edge  actually is .
  The fact that the line is shown into mid river in one small area might just be saying they DONT own to to the mid anyplace else.