The U.S government through the U.S. Fish and Wildlife Service is breeding the black-footed ferret in captivity in northern Colorado.

WELLINGTON, CO - Oct. 29: There are 48 outdoor pre-conditioning pens that house some ferrets. Each pen is 40'x40' and the animals stay in the pens a minimum of 30 days and must kill at least two prairie dogs on their own in that time frame. The U.S government through the U.S. Fish and Wildlife Service is breeding the black-footed ferret in captivity in northern Colorado. Restoring the ferrets, an endangered species, to the United State prairies is considered a key step in to reviving dying ecosystems. (Photo By Kathryn Scott Osler/The Denver Post via Getty Images)