One of my first views of what rewilding looks like in the American West was in the company of Brandie Hardman, an organic farmer and beaver fanatic in Boulder, Utah. A stream runs through her 170 acres of piñon-juniper woodlands and montane scrub in the high desert, and it was there that Hardman let the underappreciated American rodent Castor canadensis do its work. In the space of a decade, beavers transformed her land from a broken vestige to a thriving ecosystem.

When she bought the property in 2008, the beavers had been mostly killed off—five beavers remained, by her count—and the stream, its banks collapsing, held an inch of tepid water that ceased to flow in summer months. The riparian zone around the stream was cow-blasted, the result of decades of overgrazing.

In a healthy western ecosystem, intact plants on uplands and streamsides slow the downhill passage of rainwater, and this promotes the infiltration of water into soils. But when livestock consume or trample upland vegetation and crush and compact hillside soils, more water flows overland without being absorbed. The water moves faster, creating higher peak flows in stream channels, which in turn carries away the soil in a process of erosion that feeds on itself. The channels deepen and widen, disconnecting hydrologically from the riparian zone. The water is sent downstream as if in a chute.

First thing Hardman did for the rewilding of her little parcel was to kick out the cattle. Then she made the decision to stop slaughtering beaver. “The tradition with the ranchers who ran this land was to kill them,” she told me. “They thought the beavers were messing with the water supply, their irrigation lines, stealing the water, the whole gamut.”

Now, with the cattle long gone and with the proliferation of the busy animals—80 beavers by her most recent count—the stream flows year-round, two feet deep in places, backed up with ponds behind the beaver lodges. The banks are abundant with vegetation and resist erosion. The channels are narrow. The water temperatures stay cool, and the stream and riparian zone are hydrologically connected.

Less than 2 percent of the arid West consists of streams and springs, yet these are the hot spots of biodiversity, providing habitat for as much as 70 percent of vertebrate species in the region. Hardman watched songbirds return to her land with the beavers’ revivifying of the streams. With more water, there was more insect life and more food for birds. “I got into a love affair with beaver,” she told me. “It’s amazing what they do. And all you need is to let them do it. We’ve got ibises now. Almost every year, there are more migratory birds. I do beaver tours on the property. I host beaver talks. I show people pictures of what it looked like before and the incredible lushness now. I’m thinking of putting together a beaver convention.”

Beaver are at the heart of an ambitious scheme for a rewilded West that a group of 20 ecologists and biologists presented in the journal Bioscience in August. Calling for a new paradigm of management of public lands to “restore critical ecological processes with minimal human interference,” the report’s authors tied their program to President Biden’s America the Beautiful Plan, which proposes that the nation protect 30 percent of US lands and waters by 2030.

To do so in the battered American West, the authors say, we must first end livestock grazing on roughly 30 percent of public lands—about 110,000 square miles, an area equivalent to the size of Nevada. We should then reintroduce into prime spots in this cattle-free landscape two keystone species that ranchers have long persecuted: the gray wolf and the beaver.

It’s Brandie Hardman’s work on her Boulder Mountain plot, but on a grand scale—and with the addition of wolves.

“We have a climate crisis coming down the road, and we have a biodiversity crisis right now, and we know that this proposal has a chance of preventing the American West from going totally off the rails,” Robert Beschta, professor emeritus of forest hydrology at Oregon State University and one of the coauthors of the Bioscience study, told Sierra. “We think getting cattle off the land and getting these two keystone species back on are most important, because of the huge ecological consequences.”

“The beauty of this project on rewilding is that it asks seriously if society wants functioning ecosystems in the West,” William Ripple, a professor of ecology at OSU and lead author of the study, said.

Ripple and Beschta note that not only do beavers increase water and soil retention, but they also reduce wildfire risk by creating fire breaks. They increase carbon sequestration. They build rich meadows by backing up water in ponds that eventually fill with vegetation. They create an array of “moisture gradients” for more diverse plant and animal and insect species. “They are all-around multipliers” of beneficial landscape processes, Beschta said. “Once you put beaver in a system, dramatic changes start to occur within a few years.”

But for beaver to succeed, first the cows have to go.

Remove the cattle and bring back the predators

Bos taurus was never meant to inhabit the arid West. Euro-American conquest spread this invasive species to the region’s farthest corners, beginning with Spanish colonization in the 16th century. The result has been ruinous: Cattle grazing has eradicated native plants, polluted and destroyed springs and streams, removed cover for birds and mammals, and starved out native ungulates who compete for forage. Government support of grazers has had its own calamitous consequences, resulting in extermination campaigns funded by taxpayers to target predators such as wolves and coyotes.

The dire effects on landscape health from too many cows has been so wide-ranging that a team of conservation biologists concluded that grazing “may be the major factor negatively affecting wildlife in the 11 western states.” Environmental historian Philip Fradkin went so far as to assert that grazing has “done more to alter the type of vegetation and land forms of the West than all the water projects, strip mines, power plants, freeways, and subdivision developments combined.” Today, grazing is the most common use of the hundreds of millions of acres of public domain overseen by the Forest Service and the Bureau of Land Management. “Across the West, I’d rank livestock as number one in causing biodiversity loss on public lands,” Beschta said.

Consider what livestock have done to aspen forests, the second-most-biodiverse ecosystem in the West after riparian areas and the most biodiverse of all western woodlands. Cattle grazing is considered one of the chief factors in the decline of aspen stands. “Grazing short-circuits the capability of aspen to grow into saplings and then into mature trees,” Beschta said. “The roots of aspen send up sprouts, and livestock keep these sprouts suppressed. The aspen are stunted and can never grow taller. If they can’t grow taller, they eventually die out.”

Evicting cattle from the stands would seem to be the simple answer. “Pulling the cows off is an important and necessary first step,” said Beschta. “But you still have the problem of too many elk and mule deer browsing in aspen stands. That’s where wolves come in to keep their numbers down and allow the aspen to flourish.”

Decades of research into trophic cascades have shown that big predators such as wolves control wild ungulate populations, which frees plant life from excessive pressure and leads to more exuberant and diverse biotic communities. That’s because predators produce what’s called “the ecology of fear,” in which wild ungulates like deer and elk are constantly on the look-out for threats, forced to keep on the move. No longer free to linger and over-browse the vegetation, ungulates’ impacts are spread across the landscape.

Ripple and Beschta spent a decade studying the system dynamics of wolves and other predators in six national parks in North America. They found that when an apex predator is extirpated from an area, ungulates take over and stunt the growth of plants in riparian areas, with cascading negative consequences for other species that depend on those plants.

In the cougar-deer trophic system of Zion National Park, the Fremont cottonwood forests declined once the cougar were extirpated. In Yosemite, another cougar-deer trophic system, California black oak diminished as cougar numbers dropped and deer were freed of pressure from their native predator. In Olympic National Park, a wolf-elk trophic system, big leaf maple and black cottonwood declined as elk expanded after the pressure from wolves disappeared. In Canada’s Jasper National Park, a wolf-elk trophic system, aspen numbers dropped due to over-browsing from ungulates. In all these cases, overpopulation of prey species resulted in impoverished ecosystems. “The thrust of this was to understand what happens to long-lived woody plant communities when you lose apex predators,” Beschta said. “And what happens isn’t good.”

By contrast, when apex predators are allowed to return to ailing ecosystems, they regulate the system to beneficial effect, reversing the declines of plant species by killing and chasing out overpopulated ungulates.

Preservation vs. conservation

I asked the National Cattlemen's Beef Association and the Public Lands Council if they would comment for Sierra about the Ripple rewilding proposal, a plan that he and his fellow authors admitted is “controversial” and “quixotic.” There was no response. Perhaps this is to be expected. The public lands livestock industry has a strong influence in national politics, and proposals for reduction of its power have mostly been nonstarters.

Yet there’s a more serious impediment to Ripple’s rewilding vision than the studied silence of the livestock lobby. The Biden administration has taken a narrow view of how its America the Beautiful program will ultimately play out on the land. The administration explicitly states that it’s not interested in the type of preservation that Ripple and his colleagues have in mind. According to America the Beautiful, “The president’s challenge specifically emphasizes the notion of ‘conservation’ of the nation’s natural resources (rather than the related but different concept of ‘protection’ or ‘preservation’) recognizing that many uses of our lands and waters, including of working lands, can be consistent with the long-term health and sustainability of natural systems.”

This is a far cry from a rewilding that would allow beavers and wolves to run free on the western landscape, that envisions Homo sapiens relinquishing control and allowing wild things and wild processes to unfold.

“Our politics are not conducive to rewilding,” Dan Ashe, former director of the US Fish and Wildlife Service under Barack Obama and one of the coauthors of the Ripple study, told Sierra. “But it’s ambitious ideas like this that give us a blueprint so that species can continue to thrive. And yes, it means we need to sacrifice—if we want monarch butterflies, and wolves, and checkerspot butterflies, and grizzly bears, blackfooted ferrets, prairie dogs, beaver, and aspen, if we still want these species on the land, then we will have to reduce our ambitions on the land. Wildlife conservation requires constraint. It says that there are parts of the land that we will not use.”

History, he added, “tells us we aren’t very good at that.”