I live in Morgan City which is about 8 miles from the Bisland battle site west of Patterson. La. There are no visable remains of Fort Bisland to be seen. I have researched the history of this area most of my life and it seems that there is always new information coming up on the Battle of Bisland. I have even done metal detecting in the cane fields where the battle took place.If my memory is correct Fort Bisland was a three sided earthen fort right on the edge of Bayou Teche. There are houses on the site now where the Fort once was. A man made waterway called the Calumet Cut has taken up a considerable amount of the actual Confederate trenches.
Also of considerable interest is the remains of the gunboat CSA Cotton is very near in the Bayou Teche where the earthen Fort Bisland was located. I know this because of archaelogist I know who have done surveys of the Bayou Teche for the government in this area.
Many years ago I went on a research epedition to the National Archives for the Morgan City Archives. I retreaved an enormous amount of information on our area of Louisiana for the archive, including just about all of the maps on file for Louisiana during the War Between the States. I recall there was a drawing of Fort Bisland among the maps I retrived. (I hope my memory is correct about the drawing of Fort Bisland) I got all of these maps from the Architectural and Cartograpy Division of the National Archives.
I would suggest you contact Morris Raphael in New Iberia Louisiana for more on this subject. In his early years Morris worked for the Corps when they did work to create the Calumet Cut where the Confederate Battle Line (trenches)were located.
I hope this will assist you in your quest for further information.
Roland R. Stansbury