The Washington Cattlemen’s Association has inserted itself into a lawsuit filed by wolf advocates, warning that if the U.S. Forest Service and the Diamond M Ranch lose, other ranchers will lose, too.

The lawsuit pending in U.S. District Court for Eastern Washington has broad implications, according to an amicus brief filed March 5 by the association, the state’s largest group of cattlemen.

If the suit drives the Diamond M off the Colville National Forest, it will set a precedent, making grazing secondary to wildlife in national forests, particularly wherever wolves roam, according to the cattlemen’s association.

The lawsuit, brought by WildEarth Guardians, Western Watersheds Project and Kettle Range Conservation Group, takes aim at the Diamond M, the focus of wolf advocates’ fury for nearly a decade.

The suit alleges the Forest Service has failed to protect wolves, letting the Diamond M turn out cattle, inviting attacks on livestock that cause the Washington Department of Fish and Wildlife to shoot wolves.

The suit was filed against the Forest Service. The Diamond M intervened, vigorously defending its record of animal husbandry and calling accusations of wantonly leaving cattle in harm’s way absurd.

Both sides have asked Judge Rosanna Malouf Peterson in Spokane to grant them summary judgment.

The wolf advocates allege that the Forest Service has violated the National Environmental Policy Act, National Forest Management Act and Endangered Species Act and “sat idly by” as the state killed wolves.

The Forest Service argues it has served wolves by providing habitat and points to a growing wolf population, even with lethal removal. The state makes all decisions related to lethal control, the federal agency says.

Wolf advocates have been unsuccessful in suing Fish and Wildlife in state courts to stop lethal removal.

In court filings, the cattlemen’s association says the advocates are now trying to make the Forest Service responsible for managing wolves, even though wolves are not a federally protected species.

Unless Congress intervenes, states have the authority to manage wildlife, according to the cattlemen. “The entire foundation of plaintiffs’ case crumbles because it ignores this basic principle,” their brief states.

The Diamond M has grazed cattle in the 1.1 million acre Colville National Forest for more than 70 years and has never been out of compliance with the terms of its permits, according to court records.

The national forest covers parts of Ferry, Stevens and Pend Oreille counties in northeast Washington.

The ranch has permits to turn out 736 cow-calf pairs, or 1,472 head of cattle. In 2008, the ranch was the first to lose cattle to wolves migrating into Washington from the Rocky Mountains.

Wolf advocates complain that the ranch’s losses have led to the shooting of about 30 wolves since 2012. Fish and Wildlife has said that wolfpacks saturate the region and has defended its use of lethal removal as a last resort after non-lethal measures failed.

Diamond M has furthered stirred wolf advocates by maintaining that non-lethal measures have limited effectiveness against smart and determined wolves.