I don't think the Mississippi shifts that dramatically, although there are quite a few spots where the river has jumped the border. It's worse in the lower Mississippi where it's flatter and the river meanders a lot more. The terrain view highlights just how poorly located Kaskaskia is, right in the middle of the flood plain, and also reminds us that the Mississippi isn't a completely wild river like the river in Peru in that gif. You could see the levees protecting Kaskaskia and keeping the river contained in its current path.
