In 2008 for a story for Harper’s magazine, journalist Christopher Ketcham stalked the snowy, pine-filled landscape on the Montana-Wyoming border in Yellowstone National Park with a group of environmental activists known as the Buffalo Field Campaign. For decades, volunteers for the group had filmed men working on behalf of the West’s powerful agribusiness industry as they ran down and killed bison that tried to migrate out of the park. But this year, when Ketcham and the campaign asked for unrestricted access to a corral just inside the northwestern corner of Yellowstone where park employees pen hundreds of buffalo before they are trucked to slaughterhouses, the National Park Service (NPS) said no. That refusal has sparked outrage among activists beyond those concerned about animal welfare, putting the dispute over the fate of the buffalo into the realm of free speech. Late last week James J. Holman, an attorney working with the American Civil Liberties Union of Wyoming, sent park officials a letter threatening to sue the NPS. “The First Amendment aspect is what got us involved,” he said. “The bottom line is this is something that is very important to a lot of people.” The spat over press freedom is the latest twist in the fight over one of the most contentious mass wildlife slaughters in America. Yellowstone is the only place in the country where by 1900 a few wild bison (commonly known as buffalo) survived a government sanctioned mass extermination that annihilated an estimated 30 million of the animals and brought the species to the brink of extinction. That some wild buffalo were saved here was such a point of pride to the National Park Service that its emblem features a white buffalo, considered by many Native Americans the most sacred animal. Legal experts say that the battle today for a clear view of how Yellowstone employees chase buffalo into the corral, prod them onto semi-trailers and butcher them at slaughterhouses is similar to the fight against anti-whistleblower “ag-gag” laws passed in many states. Opponents say “ag-gag” laws laws deter free speech and criminalize whistleblowers, activists and journalists who are looking to expose illegal practices and working conditions. “We are hoping the park will recognize they are part of the government and they have the duty to allow the press and public to observe their activities,” said Jennifer Horvath, a staff attorney for the ACLU of Wyoming, adding that such scrutiny of public officials was a powerful way to hold them accountable.

Al Nash, a spokesman for Yellowstone, said that the park has made a video available of a biologist talking about the social struggle to conserve buffalo and that officials will take members of the press and public on a tour of the buffalo corral in a valley called Stephens Creek at a date yet to be set. Ketcham worries such a tour will be sanitized. “I want free and unfettered access to the facility,” he said, “so I can watch what’s going on, smell the blood and the feces and see the fear in [the bison’s] eyes and the way stockmen interact with them. I want to be able to document that as a reporter.” Yellowstone officials and cattle industry representatives compromised on a plan this year to cull 900 buffalo, about 1 in 5, through hunts outside the park and a capture-and-slaughter program inside the park. State and federal agencies aim to limit the bison population to 3,000 to 3,500. The Montana Stockgrowers Association, which for years lambasted the park for not killing more buffalo, said that it does not advocate mistreatment of animals and that this situation is outside its control. “Our main concern is representing the concerns of our ranchers,” said Ryan Goodman, the group’s communications manager. A big issue, he said, is fear that buffalo outside Yellowstone will eat grass out from under the mouths of domestic cattle, though some studies have argued that is not a problem. Last month Dustin Ranglack, a research associate at Utah State University, released data based on years of study in Utah’s Henry Mountains on the way domestic cattle interact with the nation’s only other herd of genetically pure, free-range buffalo — transplanted from Yellowstone in the 1940s at the behest of sportsmen. He found hardly any overlap. Buffalo, he learned, graze higher, steeper terrain than cows do and then move on. “This whole competition between bison and cattle,” he said, “has been overblown.”