The mystey of the Lagoon

Doing some digging for my "lorimer" novel, I ran across a couple of conundrums to solve: mainly that the Shawnees did not originally settle near Shawneetown, MO:

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Instead, they set up shop at the site of the district fair. Of Course, I immediately thought of Arena Park in Cape.
But my source was written in 1904. So more digging. in 1904 the fair was held at Capaha Park:

View Larger Map(Arena Park is about a mile to the west, near Kingshighway and Broadway)
The only problem was that I had already written them build semi-permanent(i.e log Cabin), which now it looks they probably built Bark huts until they found good land. Re write city here I come! here is a link with a with locations for this post.
But was the lagoon always there? Hmm.. I've been doing some searching, and have not found much luck. My guess: yes, based on the fact that sits in a depression, And did drain, and if so to where? One again, I'm not sure, but it looks there may have been an old creek bed paralleling West End Blvd 215 years ago.
And then I want to have a still as in Moonshine, you know, White Lighting

I need to have it be somewhat hidden, as I wanted my character to get in trouble for consuming a little too much. I kept on thinking that having on top of Cape Rock would work, but now I'm think it's a little close to the site of the post. Maybe I'll move the still down the river a bit. Having a bad guy fall to his death off the bluff after getting drunk on Sorghum wishkey is just too good to pass up.