So much cute in one photo – three little black-footed ferrets playing! One of the most endangered mammals in North America, black-footed ferrets once numbered in the tens of thousands, but by the 20th century, they were believed to be extinct twice. In 1981, a small population of the species was rediscovered in Meeteetse, Wyoming. Scientists captured some of these ferrets, and they became the foundation for a successful captive breeding and reintroduction program that continues today at the National Black-footed Ferret Conservation Center in Colorado. Photo by Becky Hutchens, U.S Fish and Wildlife Service.