The 4&3/16" by 1&3/16", half inch thick knife was in Norman Reid's museum in Edwards County, Illinois--considering it wasn't labeled with his name and county information I would think this was one of the pieces 'ol Norm took in (from someone local) to display, never got around to returning--his estate sale sold everything as "his collection". Regardless, the big knife is made of Attica Chert aka "Indiana Green"---since it also turns up in Illinois deposits along the Wabash River, collectors in Illinois might claim the flint as 'theirs' too. Other than the previous owner, Lower Wabash Valley is likely the only provenience I can provide for the knife.. Note the heavily use-polished round tip on this Cobbs-style knife--the tip is slick from so much ancient (Early Archaic Period) usage. The knapping of that round tip is the highest quality on the entire knife, VERY fine pressure-made flake scars. Whatever the purpose of the tip, it was the main use for the tool. Too, the base shows more skill in forming the final shape, a number of thinning flakes extending up the medial ridge--since the flake scars do not go over the center line, the medial ridge, that's one reason not to place the knife in an even earlier timeperiod (Paleo).