Stack your rocks to form a pile 3 to 4 feet in diameter and equal in height to the top of your planned fence line. While you can create the wire cylinder first, then fill it with rocks, starting with the rock pile allows you to form a sturdy rock structure and to more easily stack the rocks without having to lift each one up and over the top of the wire. Rock jacks will support up to 20 feet of fence between jacks and posts.
Wrap mesh or welded wire around the circumference of the rock pile. Use wire clips or cut and fold ends of the wire fencing to interlock them to secure the wire around the rocks.
Drive three or four metal posts to a depth of at least 2 1/2 feet around your rock jack before you run wire to or from the cage if you require extra support for the cage.
Attach the strands of fence wire directly to the rock jack using wire clips and a fence tool or a pair of pliers. Run each wire along the livestock side of the fence. Stretch and secure each section of wire as you work. A section runs between brace posts and corners. Working from the top down, install a single strand of smooth wire, as many strands of barbed wire as needed for the height and wire spacing you choose, then a final strand of smooth wire 8 inches or less off the ground, if you wish to construct a wildlife-friendly fence. For cattle, plan for a fence at least 54 inches tall, with 3 to 10 wires and 8 to 16 inches of spacing between the wires.