Web Author's Notes:
Here is a Google road map of Vicksburg, Mississippi and the battle site. It shows the approximate route of the Yazoo River before it's re-routing by the Corps of Engineers in 1878-1902 and the route of the Mississippi River before it changed course (naturally) in 1876, leaving Vicksburg without a riverfront. See maps #5 and #6 for more detail, from a current map perspective, of the battle site.
The following map created from Google Maps and editing using JASC Paint Shop Pro 7.04.