The Yazoo begins in Greenwood
at the junction of the Tallahatchie
rivers. Now Greenwood is already in that part of the Mississippi River floodplain
called the "delta
"; you'd think that the river would flow directly west
into the Mississippi River
But no, because the Mississippi has built up a series of natural levee
, the Yazoo flows south
for 100 miles or so (through Yazoo City
, of course) until it empties into the Mississippi near Vicksburg
, probably following an old course of the Mississippi2
As it turns out, a small river flowing in a larger river's floodplain, running parallel to the larger river, is a fairly common occurrence. The Delta region alone has several dozen of them. The Yazoo River has given its name to this type of landform
. The Tallahatchie River, one of the Yazoo's principal tributaries, is a yazoo. In fact, most large river floodplains will have at least one yazoo.
You can't possibly have thought that Humans thought that up on their own.
I have also heard of a theory that during the last Ice Age
, the Ohio River
didn't empty directly into the Mississippi; instead, they flowed parallel to each other through the Delta, only merging near Vicksburg.