The number of gray wolves in Washington state kept growing last year and for the first time the state documented a pack living west of the Cascade Range, wildlife officials said Thursday.

The state has a minimum of 126 wolves in 27 packs with 15 successful breeding pairs, defined as male and female adults that have raised at least two pups that survived through the end of the year, the Washington Department of Fish and Wildlife found in its annual wolf census.

A year ago, there were 122 wolves in 22 packs with 14 breeding pairs.

The pack west of the Cascade Range, in Skagit County, consists of a single male wolf, captured in 2016 and released with a radio collar, that has been traveling with a female wolf through the winter. Biologists named the pack Diobsud Creek.

"We're pleased to see our state's wolf population continue to grow and begin to expand to the west side of the Cascades," agency Director Kelly Susewind said. "We will continue to work with the public to chart the future management of this important native species."

Wolves were nearly wiped out in Washington by the 1930s but started returning to the state from surrounding areas early this century. The animals have preyed on livestock, causing conflicts with ranchers.

Gray wolves are no longer listed as an endangered species under federal protection in eastern Washington since federal wildlife officials revoked that status in 2011. They are still protected across the remainder of the state, but a pending proposal from the U.S. Fish and Wildlife Service would lift those remaining protections.

The state's census numbers were compiled from state, tribal, and federal wildlife specialists based on aerial surveys, remote cameras, wolf tracks and signals from radio-collared wolves. The count leads to estimates of the minimum numbers of wolves, because it is not possible to count every animal.

Most of the packs live in Ferry, Stevens and Pend Oreille counties in the northeast corner of the state. But the census showed increasing numbers in Washington's southeast corner and its north-central region.

The upturn in new packs and breeding pairs sets the stage for more growth this year, said Donny Martorello, policy lead for the agency.

"Packs and breeding pairs are the building blocks of population growth," Martorello said.

The agency recorded 12 wolf deaths last year. Six were legally killed by tribal hunters; four were killed by the wildlife agency in response to repeated wolf-caused livestock deaths; and two deaths apparently caused by humans remained under investigation at year's end.

The census reinforces the profile of wolves as a highly resilient, adaptable species with members that are well-suited to Washington's landscape, said Ben Maletzke, the agency's statewide wolf specialist.

Their numbers have increased by an average of 28% a year since 2008, he said.

"Wolves routinely face threats to their survival — from humans, other animals, and nature itself," he said. "But despite each year's ups and downs, the population in Washington has grown steadily and probably will keep increasing by expanding their range."

Maletzke said five of the 27 packs in Washington last year were involved in at least one livestock death.

Wolves killed at least 11 cattle and one sheep, and injured another 19 cattle and two sheep. The agency processed five livestock damage claims totaling $7,536 to compensate producers for direct wolf-caused livestock losses.