Largest wolf enclosure

The world's largest single wolf enclosure is the playpen enclosure at Mission: Wolf, a solar-powered wolf sanctuary situated in the remote Wet Mountains of southern Colorado, USA. Completed in 2016, the playpen enclosure has an area of 10.5 hectares (26 acres), and its creation for Mission: Wolf was assisted by a team of volunteers from The WildHeart Foundation, which provides direct support to animals living in zoos and sanctuaries all over the USA. The playpen enables all of Mission: Wolf's wolves to take turns to spend time within its huge, naturally landscaped terrain. Mission: Wolf currently cares for 30 wolves and wolf-dog crosses.

The chain-link tip-end fence surrounding this vast enclosure and installed by WildHeart means that when the wolves are inside it, they cannot see any fencing and hence are unaware that they are actually still in captivity. To quote WildHeart at the official opening of the playpen: "It was time to let the wolves in. The staff and volunteers of both WildHeart and Mission: Wolf walked into the enclosure and stood in one group, where they could watch the wolves explore for the first time. The pair that got the honor of being the first wolves to use the playpen was Zephir and Arrow, one white wolf, one black wolf. For the first time, these wolves could run at full sprint without being able to see a fence. They could chase rabbits, they could explore. While they sat on the top of the hill in their new enclosure, they could see all the way to the horizon as if a fence didn’t exist".