National forests fall under the U.S. Forest Service (Department of Agriculture), unlike national parks (Department of the Interior) or U.S. Army Corps of Engineers (Department of Defense). The Forest Service assimilates the gun laws of whatever state they're located in.
In other words, the OC rules in Kisatchie National Forest are the same as they are anywhere else in Louisiana. "Federal facilities", meaning buildings or portions of buildings where federal employees work, are off limits. If any of the waterways or lakes there are controlled by the Corps of Engineers, then their rules apply for that property.