The groups charge in their complaint wintertime feeding prompts elk to congregate at the National Elk Refuge, facilitating the spread of disease, The Jackson Hole Star-Tribune reported Wednesday.

Among the diseases the groups name is a chronic wasting illness that is the elk equivalent of mad cow disease. The suit also cites brucellosis, scabies and hoof rot.

Eric Keszler, a spokesman for the Wyoming Game and Fish Department, says his agency opposes halting the feeding program.

"We think shutting down feedgrounds is a solution that's too simple for a very complex problem, and it will create more problems than we currently have," Keszler said.

Among the conservation groups that have signed onto the lawsuit filed in U.S. District Court in Washington are the Greater Yellowstone Coalition, the Jackson Hole Conservation Alliance and the Wyoming Outdoor Council.