[DoodleDawg]

Mid-river fencing, on the actual border. All the way to the bottom. Water and fish will be unrestricted. People and packs, not so much. The goal is to make it so difficult that it is not worthwhile to try.

We're talking a 50 foot concrete wall. For geological and topographical reasons the may not be able to build it in the middle of a river.

[JimRed]

We're talking a 50 foot concrete wall.

Only where it is applicable. The river must flow unrestricted. Bottom line- a wall where it works, fencing where it does not for geological or topographical reasons. Surveillance in any case.