Video captured a man close interactions with a pack of wolves in Yellowstone National Park. Park visitors aren't allowed to approach the wildlife in Yellowstone, according to the National Park Service. | USA TODAY

A man approached a pack of wolves in Yellowstone National Park as visitors watched in horror from far away. Keith Allen Kerbs, who took video of the man, was taking pictures of the five black wolves when the man walked toward the animals. At one point, he was spraying bear spray at the wolves, and eventually managed to escape. The National Park Service said there have been no reports of wolves attacking humans in Yellowstone, but has still advised visitors not to approach them. | CBS News

The story of wolves in Yellowstone is a remarkable tale of reintroduction and ecosystem recovery. In the mid-1900s, wolves were eradicated from Yellowstone National Park due to hunting and habitat loss. Without wolves, the park’s ecosystem suffered, with elk populations growing unchecked, leading to overgrazing and damage to plant life. In 1995, wolves were reintroduced to Yellowstone, and their presence triggered a phenomenon known as a “trophic cascade.” With wolves hunting elk, the elk popula