MALTA — When the new West is won, will there be cowboys? In light of what her neighbors are up to, Double O Ranch owner Vicki Olson isn’t so sure.

“I guess the point that I keep hammering at is that if they succeed, that means all of us third- and fourth-generation ranchers are gone,” Olson said. She is the average Montana rancher, 56 going on 70, working a spread gouged from the pebbly soil by her grandparents 100 years ago.

Her neighbor, the nonprofit American Prairie Foundation, is methodically acquiring ranches and crafting a 3.5-million-acre wildlife reserve out of private property and adjoining federal land. The inconspicuously named Prairie Project could be the largest privately funded conservation land venture on the planet and the biggest free-roaming bison range in the United States. Yellowstone Park, at 2.21 million acres, would be a distant second.

You could watch a horse and rider traverse these treeless plains and lose sight of them only when they’re finally eclipsed by the curve of the Earth. Yet conflict here always seems to center on there not being enough room for everyone.

“If we’re completely successful, more than 90 percent of northeast Montana will still be in livestock production, be it goats, sheep or cattle,” said Sean Garrity, president of the foundation.

What Garrity and others see in this endless expanse is one of the last sustainable native grassland areas in the country, complete with 12 endemic bird species that, while not extinct, are rarely found inhabiting the same place. There are curlews and burrowing owls, sage grouse and mountain plovers. At least 180 bird species have been found here, 285 plants, 40 mammals, 15 reptiles and amphibians. The government has already made a substantial contribution to conservation in the Charles M. Russell Wildlife Refuge, a 1.1-million-acre spread that stretches 125 miles from west to east.

The American Prairie Foundation envisions a Serengeti of the Northern Plains, an expanse with wildlife abundance unseen since the Corps of Discovery two centuries ago. With the return of the wildlife, the group sees conservation research and tourism resuscitating the economies of Hi-Line towns that have been shrinking for years.

Already, the APF entertains donors at a yurt village created for seasonal backcountry camps, though Garrity said only a small percentage of the foundation’s supporters will ever come here. Biologists come and go to study grassland birds. National Geographic is producing a feature film shot on site. The foundation plans to open a full-service campground complete with a nature path and mountain bike course in June. For now, block management hunting still occurs here.

Interest in the grasslands is growing, said Jeff Hagener, a former director of the Montana Fish, Wildlife and Parks who now works for APF. He’s one of three former state or federal land management workers now working for the foundation.

“If you read about the Lewis and Clark journals, where did they talk about wildlife?” Hagener said. “They don’t talk of the mountains. They nearly starved to death in the mountains. They talk about the plains.”

Allied with the World Wildlife Fund, the American Prairie Foundation is driving hard bargains with willing Northern Plains ranchers. It has spent roughly $8 million so far buying 11 ranches. The group not only offers appraised value for the land but also sweetens the deal by allowing the sellers to stay on the property raising cattle under favorable leasing terms until the APF needs the land.

Olson said resentment is rising among locals who say they can’t compete for property with the APF’s well-funded supporters. Its national council membership includes candy heir John Mars, the 19th-richest man in America, according to Forbes, and Roger A. Enrico, board chairman of DreamWorks Animation and former CEO of Pepsi-Cola USA. Texan Bill Lively, known for raising big donations for nonprofits and big events like Super Bowls, sits on the APF’s board of directors.

“We would love to have young ranchers on these ranches. They’re interested,” Olson said. “We just can’t support the price that they’re (the APF) willing to pay.”

The ranchers’ clout will be felt when they start to disappear as the APF begins using the land it has bought for raising bison. The group currently runs 102 bison on 14,000 acres, but it will tap the other 86,000 acres it owns or leases as needed. APF also leases more than 45,000 acres of federal grazing land, which it has returned to the Charles M. Russell Wildlife Refuge.

Livestock sales in south Phillips County total $19 million. When those sales are gone, Olson said, it’s going to hurt.

“It’s not just ranchers, it’s the whole community,” Olson said. “Malta’s main street is going to see the biggest impact. Each one of those (ranching) dollars rolls over like seven times.”

Olson doesn’t expect conservation tourism to take the place of ranching. The same promises were made by government biologists reintroducing black-footed ferrets and by promoters of the region’s extensive dinosaur museum. To reach the refuge, tourists are going to have to travel down 50 miles or more of gravel roads that turn to impassible gumbo in wet weather. Even if the road were paved, there are still a lot of miles between this part of Montana and everywhere else. Not everyone appreciates flat frontier like a Northern Plains rancher.

A Washington Post reporter on assignment covering the American Prairie Foundation in 2006 wrote about this land: “The soil is bad, the weather worse and the landscape achingly dull. ... The population peaked a century ago and remaining ranchers cannot stop their children from running off to a less lonesome life.”

It wasn’t wildlife that brought people to this arid expanse. It was free land, cheap train tickets and even discounted sea passage for immigrants willing to settle the Northern Plains. Homestead filings from north-central Montana poured in at 1,500 a month as settlers pushed the state’s census rolls upward by 130,000 in 10 years. The bleached bones of the settlers’ rough-cut lumber shacks still poke through the Hi-Line’s hardpan. Their saddle-backed roofs in some cases are propped up by dressers, stoves and rotting beds abandoned by gullible sodbusters who swallowed the promise of “rain follows the plow.”

Rain didn’t follow the plow, and a painful exodus followed the prairie boom. In this country, it seems like there’s a community every 20 miles celebrating its 100th anniversary, but there are more still that never reached middle age. Sun Prairie, just north of Charles M. Russell Wildlife Refuge, is one of those places. The only trace of its existence is the name of a 30-mile gravel road, which passes by it without mention.

“You might see it on a map, but there’s nothing there,” said Dale Veseth, a third-generation rancher whose grandparents worked chuck wagons and sheared sheep before acquiring enough money to buy the property where Veseth now runs cattle.

Veseth’s interpretation of the settler exodus differs from the viewpoints of environmentalists who consider the departure proof that the land shouldn’t have been settled at all. The sheer number of homesteaders tilling and grazing this part of the prairie exhausted the land to the detriment of wildlife and ranchers. With 12 inches of rainfall in a good year, it takes 50 to 70 grazing acres to raise a single cow, depending on how much hay feeding is done. Early livestock grazing was more concentrated and unsustainable.

Veseth’s father, now 67, didn’t see an antelope on the ranch until he turned 13. There are now hundreds on the spread, which speaks to improvements in land management by ranchers, said Veseth, who has played the part of contrarian in the Boston Globe, the Washington Post and Reader’s Digest, as the American Prairie Foundation brings national media exposure to this remote frontier.

“They’ve kind of turned up the attention on this being the last best place,” he said. “And we’ve had a hand in keeping it that way. Our approach is somewhat different. We would like to work within the community, and American Prairie Foundation basically is kind of a community replacement.”

Confronted with an increasing focus on conservation, Veseth and neighbors formed the Ranchers Stewardship Alliance of South Phillips County, a group focused on changing land practices to benefit wildlife and keep ranchers in the mix.

“The first priority is to provide quality wildlife habitat,” Veseth said. “Second, in my mind, is to prove that ranching is compatible with good wildlife conservation.”

Alliance members have adopted a multilevel approach to managing the land that accommodates the individual wildlife needs of more than 12 endemic bird species living in the region, which means supporting different native grasses and grazing in a way that leaves different levels of groundcover intact.

Ranchers have gone barb-less on their bottom fence wire and raised it from 4 inches above ground to 18 inches in order to accommodate four-legged wildlife. They’ve attached reflective material to high fence wire to warn birds. They’ve added bird boards to stock tanks to accommodate winged wildlife. And they’ve worked closely with groups like The Nature Conservancy, which has also bought ranchland locally but chosen to work closely with its cattle-raising neighbors.

In 2000, The Nature Conservancy and the Tranel family of Billings and Roundup went in together to buy the Matador Ranch, which encompasses 60,000 acres of prime grassland 40 miles south of Malta. Like the APF years later, TNC recognized the importance of large grasslands to species like the ferruginous hawk, mountain plover, burrowing owls and black-tailed prairie dogs.

The group is not averse to bison. TNC just released two dozen bison into Mexico as a seed herd for grassland recovery. But the Conservancy also saw the Matador’s potential as a means for changing the conservation practices on neighboring ranches in south Phillips County. Ranchers agreeing to wildlife-friendly practices on their land get bargain-priced grazing leases on the Matador.

With little cost, the Conservancy said it has created 250,000 acres of habitat for birds and other animals. Ranchers even helped the Conservancy tag long-billed curlews to determine where they migrated. Turned out it was Mexico, a 1,250-mile trip the birds made in 27 hours.

Veseth proposed to the World Wildlife Fund that ranchers could also get involved in raising bison with a modest subsidy of 10 cents on the dollar to make up for the difference in revenue between ranching bison and cattle. The group hasn’t returned the cowboy’s call.