I haven't posted a picture of the map yet, but here's the map. This is the Army Corps of Engineers map, and the scale is huge, like six miles to the page.
What interests me about the map of the Rush River confluence is that it seems to really echo the Mississippi's own delta in the Gulf of Mexico. Look at how the Rush has built not just delta in Lake Pepin, but a long spit of land, effectively the tips of its levees!
Canoeing around all of this was a pain in my, well, shoulders. But still, it's very cool to see this microcosm of the way that moving water, with a load of silt and sand, builds land in water that is not flowing.