Wildlife agents in Washington have been authorised to exterminate a pack of 11 wolves.
They have already killed six of the wolves and are actively seeking out the remaining five members of the 'Profanity Peak' pack.
Ariel kill teams carried out the shootings.
Wolves are listed as endangered under state law, but the law allows officials to remove wolves found to be repeatedly preying on livestock.
Repeated attacks on cattle in the area have caused the state to take these lethal-control methods.
The Profanity Peak wolves are one of 19 wolf packs known in Washington.
A petition to stop the slaughter and use non-lethal methods can be found here.