ENDANGERED SPECIES -- "We don't know that we got them all, but we couldn't find any more," said Dave Ware, Washington Fish and Wildlife Department Game Division manager, explaining the agency's decision today to wrap up its mission to eliminate the Wedge Pack of wolves that have been preying on cattle in northern Stevens County.

The sixth wolf in three days was killed this morning by an agency sharpshooter in a helicopter just south of the U.S.-Canada border in the "wedge" area between the Columbia and Kettle rivers. The wolf killed today was the alpha male, who'd was wearing a GPS collar and was easy to locate. Also killed this week was the breeding female and four other adult wolves

A young female wolf from the pack had been killed by a state marksman on Aug. 7.

The one pup from the pack's 2012 litter that had been trapped and tagged was found dead of undetermined causes last month

The KING 5 TV video above shows the alpha male and the pup during their capture and release earlier this summer.

That totals 8 wolves, but doesn't explain the whereabouts of several other pups thought to have been born this year.

"The pups do a lot of howling when they're weaned, but we didn't near the howling earlier this summer, so we don't know what happened," Ware said.

"Could there be other wolves out there? Yes. We'll be monitoring. If we found one in the near future, we'd have to think about what to do. The ones we've found in the past few days have all been adults. So we've accomplish the objective and disrupted the pack. If we see something soon, we'll deal with it.

"But if we get tracks or howling a couple of  months from now, it may not be a member of this pack. It could be more wolves dispersing from Canada. We'd approach that case differently. Wolves are going to come back to the wedge sooner or later. It's good habitat."

The Diamond M Ranch, which had at least 17 cattle attacked or killed this summer on public and private land, is pulling the cattle out of the area, but the ranchers told Ware that some of the livestock can't be rounded up in the rugged forest. All of the cattle don't come in until the snow flies.