Curtis, How do I get a copy of 'your Pecks Book'?
When you say "inlet flowing into the river" are you talking about the vicinity just south of Rocky Point? I believe this is where Wright & Fischer believed it to be. The blue lines are just approximations of the old course of Flat Rock Creek and the Grand River which are now part of Ft Gibson Reservoir.
As for the article I mentioned about finding skulls in the lagoons, I'll send you a copy. Let me know your take on it.