Salt Fork River, although it looks quite a bit like an overgrown ditch. From here, it flows south, the creek in Urbana joins in, then that flows east into the Vermillion River which crosses into Indiana and eventually flows into the Wabash River which flows into the Ohio River and so forth. Altogether Urbana is about 1500 miles up stream from N.O. If rivers flow at about 2 mph, then y'all can expect to see this water down there in about 3.5 weeks, since I took this last weekend.
Here's the spot, looking south. The river is suspiciously straight.
I read somewhere that before the settlers, the region around Urbana was a series of interconnected marshy areas. The Champaign-Urbana area is also in five different watersheds, two of which in western Champaign flow to the Mississippi whereas the other three to the Ohio. All this matches the fact that the area is flat.