[jbattle]

Lake Michigan is BIG. The location of this thing isn't public but Chicago is closer to Cleveland than the middle of Grand Traverse Bay. Washington DC and NYC are closer together than Chicago and G.T.B.

I'm no expert in the Great Lakes but I'm surprised they found something that far north that old. From a little reading the glaciers were retreating from that area around the same time frame. I guess +/- 1,000 years is a big deal.

There are a bunch of cool signs of the precursor to Lake Michigan around Chicago from the time when the lake was "capped" in the north and drained to the south. Blue Island and Stony Island were real islands. Ridge road to the north marks where the shore once stood. Pretty cool to imagine.

https://en.wikipedia.org/wiki/Lake_Chicago

[robohoe]

Also the Mount Forest Island [0] in the Palos area of Chicago! This used to be an ancient island. It's also not far from Site A/Plot M Disposal Site [1] which contains buried radioactive waste from Chicago Pile 1/2/3 nuclear reactors and first home of Argonne National Laboratory [2].

[0] https://en.wikipedia.org/wiki/Palos_Forest_Preserves [1] https://en.wikipedia.org/wiki/Site_A [2] https://en.wikipedia.org/wiki/Argonne_National_Laboratory

[AlbertCory]

Interesting. I grew up in Roseland, and there was a hill east of Michigan Ave. going down. I always thought that was from Lake Calumet which used to be a lot bigger.

[dhosek]

Where I live in Oak Park, there is a ridge on the appropriately-named Ridgeland Avenue, which marks the shore of the ancient Lake Chicago. I think my current home would have been in marshy shoreland.

Edit: Just looked at the article, and see that Ridgeland avenue is listed as one of the shoreline areas in the article.