Types of "Fencing" on the US/Mexico Border

 Single-layered fence

Naco, Arizona

Mostly 14' airport matting.

There are variations in this construction resulting in a higher or lower fence.

Not very effective

 Two-layered fencing

San Diego

  Railroad rail vehicle barriers

Easily defeated by cutting at the weld for removal at will or by using a ramp.

  Round bollard vehicle barriers

Goldwater Bombing Range

Supposed to be filled with cement but many sections such as the one here near Yuma were not.

Smugglers can cut them in a way that allows the fence sections to be removed for drive-throughs.

Square bollard vehicle barrier

Organ Pipe National Monument

These were filled with cement.

Ramps can be used to drive over the barrier.

Barbed Wire Stock fence

Ladd Ranch in Arizona

Many breaks were seen in the stock fence all along the border
No fence or totally destroyed

East of Calexico,California

At least 100 miles of the border have no fence at all. Much of this open area is on and near the Goldwater Air Force Range in Arizona. The rest is spotted along the border.