Everyone knows (uh, right?) that bison used to be ubiquitous across much of what became the United States, especially in the plains, and that European settlers set off a massive annihilation of the ungulates. Estimates of the number of North American bison, pre-colonization, range from 30 to 50 million. By the start of the 20th century, some estimates put the total number at around 1,000.

If you've been to Yellowstone or any park or preserve containing a "conservation" herd of bison, you know that we've managed to pull bison back from the brink. If you've eaten a bison burger, perhaps this is even more obvious.

What saving bison means and does not mean, however, is a hotly debated topic because the goals of wildlife conservationists and those of commercial bison and cattle ranchers are at odds. The former wants wild herds to roam freely over wide swaths of public land. The latter already uses much of that land and worries that bison will compete for forage with its livestock.

There are other issues, too, such as concern that brucellosis, a bacterial infection present in some wild bison herds, will be transferred to domestic cattle and bison herds if the wild bison roam wide and, well, free. Plus, private land-owners worry wild bison will trample their fences to get at hay or water during drought. Bison ranchers who graze their stock on public land worry about this, too, because what is to keep a landowner from shooting a bison he finds on his land and assumes it's wildlife rather than livestock?

Montana is ground zero for this emerging range war because many Yellowstone bison carry Brucella (the bacteria that causes brucellosis) and move down from the highlands during the winter, toward grazing lands outside the park. The Park Service has been wrangling with the livestock industry for decades over this issue and worked out a sort of compromise that allows for some bison to roam into rangeland outside the park as long as they are ushered back into the park after winter. Nevermind that no one has documented any cases of cattle contracting brucellosis from bison outside of experiments in which the two animals were closely penned together. Montana ranchers go to lengths to keep brucellosis-free stock, which can be shipped out of state without costly testing.

A newly-released report by the Department of Agriculture shows that Brucella can be reliably removed from Yellowstone bison, through quarantine and treatment. This, in theory, should allay the livestock industry's concern around the disease. It seems it will do little, however, to quell the larger battles—which exist not just between wildlife folk and livestock folk, but also between bison ranchers and wild bison advocates.

Much of that contention is around the wild bison genome. A long history of cross-breeding with cattle means that only a small percentage (the American Prairie Preserve estimates 1.5 percent) of bison alive today are truly not hybrids. And the wild genome is being degraded, wildlife advocates argue, by bison ranchers using artificial selection to encourage certain traits.

"Evolutionary natural selection is what produced wild bison. Evolution has not ended, and natural selection is necessary to maintain the characteristics of wild bison, over the long haul," says James Bailey, a retired professor of wildlife biology at Colorado State University and author of American Plains Bison: Rewilding an Icon. "We don't leave bison to future generations of Americans. We leave the bison genome."

Dave Carter, executive director of the National Bison Association, a trade group that promotes bison ranching, argues that one can't make blanket statements about ranchers monkeying with bison genes. "A lot of ranchers have bulls and cows in pastures and they sort it out in the rut. It's all romance in the pasture," he says.

Carter notes that some of the larger producers, such as Ted Turner and Dunham Ranch, do manage herds for specific traits. Still, he says, bison ranches do not artificially inseminate their stock, do not use growth hormones, and use antibiotics only to treat illness. "Bison producers in Montana have worked hard to demonstrate that they are good neighbors with the cattle business," he added.

Bailey pulls no punches when it comes to the influence livestock industry has on wildlife conservation efforts. "The ag industry does a good job of promoting themselves as the last real Americans and all that," he says. "[As if] they're the only people with family values and that kind of stuff. Then there's the Marlboro man.

"I don’t think the livestock industry should be controlling our public lands to the extend that we have privately-owned cattle on almost all of our public lands and public bison on none of them [outside of special herds in national parks and forests]."

The Nature Conservancy and the American Prairie Preserve both support wild bison herds on their respective conservation landscapes. And the National Wildlife Federation is working to restore bison to Montana's 1.1-million-acre Charles M. Russell (CMR) National Wildlife Refuge, as part of a larger program to address wildlife-livestock conflicts and restore the prairie grasslands to their natural state. A major tenant of this program is an "Adopt a Wildlife Acre" fundraising campaign, in which NWF uses donations to offer ranchers a fair price in exchange for their agreement to retire their public land grazing leases.

"The Wildlife Refuge is supposed to be for wildlife, but we are leasing it out for cows," says Bailey. "So the National Wildlife Federation is using public funds to pay [ranchers] not to graze our land. It doesn't make much sense but that's been a pretty common thing around the country."

So, aside from working to restore wild bison in pockets around the West, what can be done? Without a significant percentage of Americans giving up beef and therefore reducing demand for livestock grazing, there's no clear answer. Bailey says two attempts to gain federal protection for wild bison through the Endangered Species Act, failed.

"Around 2009 I submitted a proposal to list bison in the U.S. as a threatened species, but the meager response I got from the Fish and Wildlife Service, in my opinion, should be an embarrassment to the Fish and Wildlife Service," he says.