The concrete hazards that Nimrod is talking about are right in the center of the old river channel on the East edge of English Branch where it emptied into the Fourche River. I can't remember if they are as I have them drawn or they may be North and South of each other. Now that I think about it maybe they are oriented opposite of the way I have them drawn. They are located North of the rock bluff on the South side of the lake.
These supported the old railroad that used to cross the river at this location. Use extreme caution in this area. I hope this info will save a few lower units during this drawdown.