Nature provides the evidence. Species of wildlife that were rare a quarter century ago are now encountered routinely, even if they are not exactly common. Moose are back. Elk are back. There are persistent reports of bears on the periphery of the Red River Valley.
Wolves are out there.
Even, if back-country enthusiasts are to be believed, cougars. Prairie chickens have been re-established. If bald eagles aren't nesting along the Red River now, they will be within a few years. But there are specific areas, with known boundaries, that are going over to wilderness. The best example is the forest zone along the Red River.