The wolf pack had been responsible for 29 depredation incidents on cattle since 2018, according to the WDFW.

SPOKANE, Wash. — Editor's note: The above video is from a 2018 story on the controversy over killing wolves in Washington state.

All members of a wolf pack that had been preying on cattle in Washington state have been killed.

The Washington Department of Fish and Wildlife announced Friday that the four remaining members of the OPT wolf pack in Eastern Washington's Ferry County had been killed.

The wolf pack had been responsible for 29 depredation incidents on cattle since 2018, the agency says.

Agency director Kelly Susewind authorized the deaths on July 31.

This is the fourth time Director Susewind has authorized lethal removal in the OPT pack since Sept. 12, 2018

Environmental groups opposed the killings, which they contend benefit only one ranch operation in the Kettle River range.

Earlier this month, a conservation group filed a lawsuit seeking to prevent the state of Washington from killing more wolves from a pack that is preying on cattle.

The Maryland-based Center for a Humane Economy filed the suit in King County Superior Court, contending too many wolves have been killed as a way to protect livestock at a single ranch in the Kettle River Range in Ferry County.

The center and other conservation groups say it may be time to consider moving the cattle off Colville National Forest grazing lands that are also prime wolf habitat.

Most of the wolves are located in the rugged mountains of northeastern Washington, but they have started spreading to other areas of the state.

Officials say the state now has at least 126 wolves in 27 packs with 15 successful breeding pairs. For the first time, a pack has been found living west of the Cascade Range.

The Washington Department of Fish and Wildlife believes it has removed all members of the OPT pack, although another wolf was sighted in the area this spring. It may be from another pack.

The department tracks wolf pack behavior and population as a part of their Wolf Conservation and Management Plan.

There were 27 wolf packs in Washington by April.

The WDFW will be holding an open house in Clarkston to discuss wolf post-recovery management plans.