Late one night in October, 2017, Jane Marx, a landscape architect in the wine country of Northern California, woke up to the smell of smoke and the sound of an eerie, howling wind. She dialled 911. “There are three fires in your area, and we’re on it,” a dispatcher told her. But the blazes, sparked by downed power lines, quickly spread. Fire raced up a thickly forested mountainside and moved west into Bennett Ridge, the idyllic rural development where Marx lives. Soon her subdivision was engulfed in flames. Propane tanks were exploding nearby. Marx and her husband, David, had recently returned from a trip. They threw their still packed luggage into two vehicles and fled. “It was just ‘Run for your life,’ ” she told me.

The conflagration, known as the Nuns Fire, destroyed 1,355 buildings, including most of Bennett Ridge. Marx’s home survived, but her two and a half acres of land were torched. Locals who decided to stay in the area formed a community fire-safety organization. Still, anxiety levels spiked during red-flag fire weather. Orange sunsets over the Pacific, which was visible in the distance from Marx’s house, gave her panic attacks. She worried about tall, flammable grass that grew toward the rear of her land. It was difficult to trim, because the rocky terrain plunged steeply downward, toward a valley. Residents were learning that the region’s temperate weather wouldn’t protect them from conflagrations: between 2017 and 2020, six catastrophic wildfires scorched California’s wine country. The area’s forests, shrublands, and grassy foothills were perilously overgrown.

Communities can reduce their fire risk by thinning out grass, brush, and trees with weed trimmers, mowers, and chainsaws. It’s also possible for firefighters to set prescribed fires, to prevent vegetation from accumulating out of control and fuelling wildfires, but that comes with its own risks. Marx’s grandfather had been a sheep rancher, and so she had always wondered if there was another way. What if hungry sheep or goats could come eat the grasses? She called some grazing businesses, but they said that their animals grazed on tens of acres at a time. Her property wasn’t worth their while.

Then, three years ago, a neighbor named Bill Hill, who had recently purchased four burned-out acres, attended a webinar about community grazing coöperatives in Sonoma County, where Bennett Ridge is situated. One speaker, a local named Sarah Keiser, maintains what’s known as a “flerd”—a small flock of sheep combined with a small herd of goats. She noted that the animals not only prune highly flammable invasive plants but also fertilize the soil, giving fire-resistant native species a better chance at surviving. “What we were talking about is turning a burden”—overgrown grass and brush—“into a resource,” she told me. With Keiser’s guidance, Hill, Marx, and another neighbor decided to organize their own grazing coöperative. Keiser, who runs a consulting firm called Wild Oat Hollow, would play the role of matchmaker—setting up the homeowners with farm animals that could graze their lands.

Livestock have been reshaping landscapes since humans first domesticated sheep, goats, pigs, and cows, about ten thousand years ago. In the Mediterranean region, forests were gradually cleared away by a combination of slash-and-burn agriculture and grazing. As hunter-gatherers became farmers and herders, they cultivated crops, vineyards, orchards, and grassy pastures. They periodically burned farmland, to renew it, and their grazing animals helped prevent trees and brush from regrowing. By the time of the Roman Empire, Europe was a mosaic of woods, grazing lands, and farms. On the Iberian Peninsula, a sophisticated kind of agroforestry combined all three. Mixed-use pastures known as dehesas were planted with crops and peppered with oak trees, which provided cork and firewood. Depending on the season, animals could eat the crops, graze grass, or forage for acorns.

More recently, as the planet has warmed and wildfires have raged, the wisdom of these ancient ways has become more evident. History has shown that excessive agricultural burning can wreak environmental havoc, as can overgrazing. Yet in the twentieth century, when countries around the world prioritized the suppression of all wildfires, many areas became overgrown and susceptible to firestorms. In recent decades, meanwhile, some rural communities have shifted away from farming or have emptied out, leaving behind untended lands where vegetation runs rampant. This summer, when wildfires erupted in Spain, France, and other parts of Europe, experts cited land abandonment as a factor. Research generally finds that grazed, cultivated, and irrigated fields are much less vulnerable to fires, in large part because they keep “fuels” in check. Dehesas have been found to be particularly fire-resistant. (There are important caveats, of course; one Spanish analysis found that mosaics of small plots are more prone to blazes, not less, and some wildfires are inadvertently triggered by agricultural burning.)

Such lessons seem relevant to the situation in California, too. Agriculture has ebbed in many places, as have prescribed burns, leaving behind what Keiser called an immense “fuel load.” She argued that “the reduction of pastoralism and agriculture” in California’s wine country has contributed to its fire disasters. The state also has a Mediterranean climate where invasive grasses, originally imported by European colonizers and their farm animals, flourish madly after winter rains and then die back during rainless summers. According to Lynn Huntsinger, a rangeland-ecology professor emerita at the University of California, Berkeley, the state could slow the spread of fires by actively fostering mosaics of grassland, woodland, and cropland—and, she argues, grazing by cows, sheep, and goats ought to be part of the solution. In a 2021 paper, she wrote, “California faces a massive fire problem, and our most active fuel managers should not be left in the barn.”

The strategy of “prescribed grazing”—deploying livestock to reduce fire risk, or to accomplish other goals—is gaining momentum in California. The state’s wildfire-resilience plan calls for scaling up the approach. Wildfire-preparedness initiatives have increasingly brought livestock into public parks and nature preserves. The University of California Cooperative Extension set up a no-frills website called Match.Graze to help connect landowners with ranchers, also known as graziers, who have livestock for hire. Keiser alone has helped create around thirty community-grazing coöperatives; many have received grant support from the LandSmart Grazing Program, a publicly funded conservation initiative for which she is a consultant.

In 2024, Marx, Hill, and several neighbors hired a grazier to bring goats and sheep to nineteen properties in Bennett Ridge. “It was very stressful,” Marx told me. A wet winter and spring helped grasses grow unusually tall, and that slowed the grazier down; by the time he got to the neighborhood, the grasses were “so high and so dry” that some anxious homeowners had given up on grazing and brought in weed-removal firms. But, this year, twenty-two properties participated—many of them twice. In March, after significant winter rains, a different grazier named Paigelynn Trotter, the owner of Coastal Land & Livestock, trucked in three hundred and forty cashmere goats. After setting up temporary paddocks out of portable, electric-net fencing, Trotter’s crew shuffled the animals from one area to the next in the course of a month. The goats ate their way through verdant grasses, woody shrubs, and invasive weeds such as Italian thistle and foxtail barley, entertaining their hosts all the while. “It’s way better than TV,” Hill recently told me. He recalled watching goats climb onto the lower branches of trees so that they could devour leaves and twigs.

Sonoma County had a rainy late spring, so the vegetation rebounded and began drying out, leaving behind more kindling for fires. Coastal Land & Livestock returned in early June with six hundred sheep, rented from Kaos Sheep Outfit. To see them at work, I drove up from my home, near the Bay Area, passing vineyards and climbing a narrow, winding road into the subdivision. When I arrived, the docile ewes had already chomped through half a dozen parcels.

Hill, a graying seventy-one-year-old with bushy eyebrows, drove me around in an all-terrain vehicle. The sheep had recently been sheared, giving their woolly coats a sculpted, Cubist look. I watched as they foraged through dry vegetation, sometimes sticking their faces into tall, prickly thistles and coyote brush. A gentle hubbub of rustling, munching, and occasional bleating filled the air. “It’s amazing, huh?” Hill said, chuckling happily.

The next morning, at seven-fifteen, I returned to see Trotter’s team move four hundred sheep about half a mile up the road. The ridge was shrouded in coastal fog; a few members of the grazing co-op had gathered to help. Trotter, who was wearing a lemon-yellow hoodie, with brown hair tied back in a bun, reminded me of a coach who was reviewing the day’s game plan.

To steer large numbers of sheep and goats, shepherds can apply “pressure” by standing in the right places, Trotter explained. Their goal was to escort the mob to their next dining spot—i.e., the end zone—while keeping them on the road. She would be positioned along the flock’s left flank while one of her employees, a woman in a turquoise sweater, covered the right; another would manage the tail end of the herd with help from a young border collie. Trotter’s husband, a farmer, was to block traffic by driving ahead in their gray pickup truck; their five-year-old son and infant daughter were along for the ride.

Suni Levi, one of the co-op leaders, was tasked with guarding her driveway and front yard. The remainder of the hired livestock, about two hundred ewes, were in a nearby back yard; Levi had to make sure that the others didn’t trample through her garden to join them. “If they start to look at your yard like they’re gonna come in there,” Trotter said, “pretend you’re a bubble and go, ‘Ah, ah, ah, ah, ah!’ ” She lifted her arms so that her body formed a “T,” sashaying left and right in imitation of a defensive sheep-blocker. But don’t wave your arms too wildly, Trotter added, or the animals may try to run past you. Levi, who had a mane of flowing white hair, nodded. “Enjoy the show,” the grazier said. Then she headed off to fetch the flock.

I joined Levi in her driveway. We watched as the gray pickup cruised past us, and soon we heard mahhh-ing. Trotter was shouting instructions. The sheep were straying from the road, veering through the front yards of homeowners who weren’t in the grazing program. “Uh-oh,” Levi said. But the shepherd in turquoise ran up alongside the flock, turning them back toward the road. Sixteen hundred hooves trotted past Levi’s driveway. (There was no sign of the border collie; he turned out to be injured.)

The mob zigzagged a few more times, with the herders in pursuit. Finally, the sheep made it to the end zone, a two-acre property covered in a sea of dead invasive oat grasses. The shepherds were winded. “No one needs to go to the gym!” Levi joked.

Trotter’s team had prepped the property with water troughs and alfalfa hay, which drew in the animals. “They just dumped right into their paddock beautifully,” she told me. Since the last time the area had been grazed, a year earlier, the grasses had grown to chest height and then folded under their own weight. The sheep immediately waded in and chowed down.

The landowners in the grazing co-op paid Trotter’s company sixteen hundred dollars per acre for its services—roughly what a larger property might spend on a weed-removal firm. When I asked if she considered the effort a success, she admitted that, logistically, grazing Bennett Ridge is “a little bit of a nightmare.” For twenty-three days of summer grazing, her crew had needed to erect and dismantle twelve thousand yards of fence line. Moving the sheep through the neighborhood was “nerve-racking,” she told me. “They’re living animals that have their own minds.” But the project was also gratifying, she said, because the co-op had secured strong community support and taken on organizing work that made her job easier.

After the Great Sheep Chase, the flock grazed for about twenty-four hours before moving on. Levi texted me photos; the out-of-control grass-scape had been pared back to a short, scruffy layer. I e-mailed the images to Ben Nicholls, who had recently left his position as a division chief at Cal Fire, the state firefighting agency, to head up a nonprofit called Fire Safe Sonoma. A bit of cleanup was still needed around some trees, he told me in a phone call, but the landscape was clearly a lot safer. He used an algorithm to model the impact of a fire in the area. Pre-grazing, if a tossed cigarette butt or a downed wire had sparked a blaze on a warm, moderately windy afternoon, flames at least twenty feet tall would have spread quickly and likely climbed into the treetops. But, post-grazing, the same scenario would have ignited slower-moving five-foot-tall flames that firefighters would probably be able to manage. “It makes that fire much easier to control,” he said. Fire crews responding to major fires have sometimes witnessed flames slowing down when they reach a grazed park or pasture.

At Cal Fire, Nicholls pushed for prescribed burns that could create a protective buffer zone in a nearby state park, making wildfires less likely to spread to Bennett Ridge again. A few years later, his plan remains only partially executed. Many locals worry that a prescribed fire could escape control or cause smoke damage to winery grapes. In some landscapes, he said, “it may be far easier to run animals through it than to try to burn it.”

Hill, for one, wishes that controlled fires could help tame the vegetation in the steep, rocky landscape behind his newly built house. But setting a fire in a subdivision seems too risky. “The animals, I think, are probably the safest thing we’ve got,” Hill told me. “The worst they do is eat somebody’s ornamental trees.” Video from Hill’s property in June made the grazing process look almost like a magic trick. When the sheep first arrived, the dead grass was so high that the animals literally disappeared into it. But, as the sheep munched, they gradually reappeared, and the grass vanished instead. ♦