Our large yard, for our high-contents, boasts a 9-gauge chainlink that is 8' tall with a 2' lean-in at the top, and a 3' skirt at the bottom to prevent them from digging. It's very expensive but well worth it!
We get many people who think that a standard six-foot fence made of wood is sufficient for a wolfdog--or no fence at all--because the dogs should "feel free to roam". This is absolutely wrong! A loose wolfdog can often be found as a dead wolfdog, ie, shot by someone, hit by a car, captured and possibly euthanized, etc.