In this Friday, Sept. 23, 2011 photo, wildlife biologist Paul Marinari, left, releases an endangered black-footed ferret into the wild, in the Badlands National Park near Interior, S.D. Watching, from left, are Bob Henderson, Don Fortenbery and Con Hillman. Hillman and Fortenbery formerly worked for the U.S. Fish & Wildlife Service; Henderson is retired from South Dakota Game, Fish & Parks. The release of male ferret No. 7505 kicked off a weekend of ferret festivals nationwide to celebrate the 30th anniversary of the ferret's rediscovery in the wild. Conservationists say they hope to be able to remove the ferret from the endangered-species list by 2020.

In this Friday, Sept. 23, 2011 photo, wildlife biologists release black-footed ferret No. 7505 into a prairie dog burrow in the Badlands National Park near Interior, S.D..