Federal judge refuses to block release of wolves in Yellowstone

A clerk at the federal district court in Casper, Wyoming, said Judge William Downes denied a request for a preliminary injunction against the release, paving the way for officials to free the 17 wolves from temporary pens at Yellowstone.

Sharon Rose, spokeswoman for the U.S. Fish and Wildlife Service, said the wolves will probably be released in the middle of April. "We're not running out and opening the pens. The lawyers have to study the decision," she said.

The animals were captured and transported from the Canadian province of British Columbia earlier this year.

The judge had previously issued only a temporary restraining order to prevent the U.S. Fish and Wildlife Service from releasing the gray wolves from the pens.

The Montana Stockgrowers' Association and a Montana rancher had asked the judge to issue a preliminary injunction to keep the program on hold until a full trial on its merits is heard. "We're pretty disappointed with the outcome and we will be reviewing our options," said a spokeswoman for the Helena, Montana, ranchers group.

Wolves have been absent from the northern Rocky Mountains for more than 60 years. Ranchers fear the wolves will not be contained in the park and will kill livestock.

Another lawsuit on the matter is pending, but no decision has been made in that case.

This story written by Reuters correspondents