Diamond M Ranch cattle are rounded up on the ranch’s winter grazing ground in southeast Washington. The ranch on Sept. 18 filed a motion in federal court seeking to defend itself against claims it doesn’t try to avoid conflicts with wolves in northeast Washington.

A federal judge has dismissed a lawsuit that sought to drive Diamond M ranch cattle out of the Colville National Forest in northeast Washington.

U.S. District Judge Rosanna Malouf Peterson in Spokane rejected claims that the Colville forest’s 2019 management plan failed to address how grazing on Diamond M allotments affects wolves.

Peterson ruled Friday that the plan didn’t harm wolf advocates because it’s not the document that authorizes Diamond M to graze 736 cow-calf pairs on five allotments. Grazing permits, individual allotment plans and operating instructions allow the grazing, she said.

“This is good news,” Diamond M partner Len McIrvin said Monday. “That is the right ruling.”

Wildearth Guardians, Western Watersheds Project and Kettle Range Conservation Group alleged the 2019 plan violated the National Environmental Policy Act and the National Forest Management Act.

Kettle Range director Tim Coleman said the groups will consider appealing.

“You can’t say the forest plan doesn’t have an effect. It most definitely has an effect,” he said.

The lawsuit was one of two filed last year by environmental groups seeking to curtail or stop grazing in the 1.1 million-acre Colville National Forest.

The second suit, still pending, alleges grazing in the national forest harms the environment. Peterson, an Obama appointee, presides over that suit as well.

The Diamond M, the region’s largest ranch, has been grazing cattle in the Colville National Forest for more than 75 years. Wolf advocates complain that the Washington Department of Fish and Wildlife has been too quick to shoot wolves for attacking Diamond M cattle.

The ranch intervened in the lawsuit and vigorously defended its practices. The Forest Service argued that the state’s growing wolf population belied claims that it was harming wolves.

Efforts to obtain comment from the agency on Peterson’s ruling were unsuccessful.

The unresolved suit was filed against the Forest Service by the Lands Council, Western Watersheds Project and Kettle Range Conservation Group.

The suit alleges the 2019 forest plan allows excessive grazing that damages the ecosystem.

Peterson has allowed the Washington Cattlemen’s Association, Washington Farm Bureau, the Stevens County Cattlemen’s Association and Public Lands Council to intervene in the lawsuit to defend grazing.