A Darby area rancher says he shot and killed a female gray wolf that was mixing with a herd of horses on his property.

Jeff Rennaker, manager of the Two Feathers Ranch, says he went out at 9 a.m. Tuesday to feed the cattle when he saw a wolf in with the ranch's 13 quarter horses.

He says he used a shotgun to kill the wolf, which wildlife officials say was a 70-pound yearling.

The Trapper Peak Pack was first documented in 2007 and has a history of interacting with livestock, horses and domesticated animals. One wolf killed a calf in 2009, and a second - the pack's alpha male - was killed while attacking a dog. A wolf was removed from the pack to address the conflicts.

The wolf killed Wednesday was not the alpha female.

Copyright 2010 The Associated Press.