Hunting groups in Montana are challenging a plan to reduce the spread of disease to cattle by allowing landowners to fence out and kill elk.
The Skyline Sportsmen's Association and Anaconda Sportsmen's Club filed a lawsuit against Montana Fish, Wildlife and Parks on Wednesday seeking to block the plan.
Montana wildlife commissioners last month approved measures to prevent elk and cattle from commingling in parts of Park County where brucellosis has been detected.
The disease can cause cattle to abort their calves and is carried by some elk.
The brucellosis plan allows officials to issue elk kill permits to landowners through May 15. Ranchers also can ask the state to pay for elk-proof fencing in the spring, when the chance of disease transmission is the greatest.