I've been over the area recently and am convinced that most of the battle site from the Hay Camp Fight is well above water. The original route of the Texas Road can still be traced and a number of the other key landmarks mentioned in the accounts of the battle also still exist, so it is pretty easy to place the primary site of the fight as west of the modern highway.

The artifacts found in the water, I believe, result from some of the Union soldiers who were trapped along the banks of the creek and killed.

Dale