The pack of grey wolves ranged just south of Christina Lake, B.C., into Washington state and had developed a taste for cattle.
One rancher estimated more than three dozen of his calves had been injured or killed.
This week, a government marksman began shooting the pack from a helicopter. So far he has killed six wolves — more than half the Wedge pack — including the alpha male and female.
"We felt we had no choice in this case because over the course of two or three months this summer this pack had increasingly exhibited an attraction to livestock as its primary food source," said Bruce Botka, who is with the Fish and Wildlife department.
Wolf kill highly controversial
The Wedge pack consists of at least eight grey wolves, whose range includes a remote, wedge-shaped area of northern Stevens County bordered by Canada and the Columbia and Kettle rivers.
The grey wolf is an endangered species that after being eradicated more than a century ago, has been reintroduced to Washington state.
The kill angers wolf lover Shelley Black, who raises wolves and runs Northern Lights Wildlife Wolf Centre near Golden, B.C.
"Killing the species off again. It's just barbaric. It just shows we are still set back in the early 1900s," said Black.
The wolf kill is highly controversial in Washington, but officials have committed to taking out the entire Wedge pack.
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