Some Kids Play Sports. These Kids Train Wild Horses.

Maggie Shannon for The New York Times

In the remote northeastern corner of California, wild mustangs roam the landscape. But over decades, their populations have grown to the point where they threaten fragile ecosystems, frustrating locals.

So the people in charge of managing the wild horse population thought of an idea: Have children from across the state adopt and train them. After six months, they would show off their skills at a competition.

The mustangs weren’t the only ones who learned new skills.

The Devil’s Garden Colt Challenge taught the young participants how to train a horse — and much more.

The Devil’s Garden Colt Challenge offers a solution to California’s overpopulation of mustangs.

ALTURAS, Calif. — The young mustangs cantered restlessly in the snow around Double Devil Wild Horse Corrals in December, their coats thick and unkempt.

Several months earlier, they were born in the rugged, arid grasslands of the Devil’s Garden Plateau in the Modoc National Forest, a remote corner of Northern California that bears little resemblance to the beaches and cities most people know.

The mustangs cut striking figures as they galloped across the wide-open lands, descendants of horses that once proved useful to the U.S. cavalry and farmers. But more than a century of largely unchecked reproduction has led to a population explosion well beyond what the land and residents can tolerate.

Wild horses devour the plants and trample the streams that serve as crucial habitat for native species. To reduce their impact on the fragile ecosystem, the federal government gathers up hundreds of the horses each year and takes them to corrals, ideally to be adopted by people who have the space, time and wherewithal to tame them.

That’s where the Devil’s Garden Colt Challenge comes in.

Late last year, 40 children from across the state were selected to take a special set of horses home. Over six months, the mustangs would grow accustomed to being fed, brushed and walked. And their young caretakers would, in turn, learn responsibility, gentleness and humility in the face of nature.

In June, about 20 of the horses returned to Modoc County, their manes brushed, braided or spangled, for the culmination of the challenge: a horse show to test all that the mustangs — and their trainers — had learned.

The colt challenge aims to attract a wide range of young equine enthusiasts — from horse novices to those who have grown up caring for the animals.

Liberty Gonzales, 13, fell squarely into the latter category.

At her home in Turlock, in California’s Central Valley almost 400 miles south of Devil’s Garden, she has dozens of equine figurines known as Breyer horses. Her older sister rides horses, as do her mother and her aunt.

On a family camping trip last summer, she saw the Devil’s Garden mustangs at a corral.

“Liberty wanted us to bring home a horse that day,” her mother, Joy Gonzales, recalled.

The girl applied for the next colt challenge. By winter, she met Bernie, a petite, chestnut-colored gelding. Immediately, she began a training regimen with clear milestones, starting with being able to pet him on their first day together.

“It’s a kind of important thing,” Liberty said.

She accomplished that goal. But not all of the training went according to plan. Initially, Bernie was too spooked by a harness to be walked — he took off and would not let Liberty catch him.

“It’s very different from a horse that was born in captivity,” Joy Gonzales said. “You have to win his trust — he’s a 600-pound feral animal who thinks you’re out to eat him.”

Ben Silveira, 10, had to learn that lesson by enduring a few nips and side kicks from Buddy, the Devil’s Garden mustang he adopted.

“It’s definitely been an adventure,” Cheri Silveira, Ben’s mother, said a few months after they brought Buddy home to Turlock.

The Silveiras were new to horse ownership. But as they planned to move to Tennessee to a home with more land for horses, Ms. Silveira saw an opportunity.

Ben plays baseball and takes karate lessons. He was a little surprised when his mother proposed that he consider equine training.

“I was just minding my own business, and she came up to me and said, ‘Hey Ben, want a horse?’” Ben said.

At first, Ben was not allowed into the pen with Buddy. But gradually, with the help of alfalfa cubes, Buddy got comfortable enough for Ben to pet him, then brush his fur, then halter him. Then, the horse needed to be desensitized to the sights, sounds and textures he might encounter. Ben slowly exposed Buddy to flags, foam pool noodles and the horse trailer, all coupled with treats.

Buddy, the Silveiras learned, could be stubborn. The horse held a grudge for days after Ben brushed his leg — “and he just hated it,” Ben recalled. But the boy became devoted to the young bay mustang.

“I was just really happy he came and ate out of my hand,” Ben said, recalling an early bonding moment.

***

To the uninitiated, the 74th annual Modoc County Junior Livestock Show in June was a disorienting swirl of activity.

Goats and sheep crisscrossed by spectators in cowboy hats and camouflage. Teens wearing crisp, white button-down shirts tucked into their jeans huddled in front of a snack bar that served piping hot cheeseburgers. Rows of livestock pens were decorated with artificial flower garlands and hand-glittered signs.

To the residents in these rural reaches of California, the livestock auction serves as a kind of annual revival, a celebration of an agrarian way of life that has been gradually receding for decades.

“It’s important for kids to know where their products come from,” Todd Hughes, a biology teacher from nearby Cedarville, said. He had brought his children to the event and watched the hogs nosing around the pen in front of him. “You’ll see a lot of tears of appreciation and respect for the animals.”

But even among livestock fans, wild horses can be a source of tension and frustration. The region’s cattle ranchers bristle at the strict rules that govern when they can allow cattle to graze on federal land and for how long, while wild horses can roam freely and chew up grass.

“The horses are just wherever they want to be,” said Zack Hannah, a cattle rancher who watched his daughter dart around the livestock show. “It’s not only wrecking the county,” he added, but the horses are often undernourished when they’re living in the wild.

But Mr. Hannah praised the colt challenge for not only reducing the horse population but getting more young people across the state interested in ranching or other agricultural industries.

Charlea Johnston, a U.S. Forest Service staff member who manages the Double Devil Wild Horse Corrals, said that the program was also meant to help reduce the stigma around the mustangs, who can make great ranch or rodeo horses with care and training.

“This herd is known to be versatile and easygoing,” she said.

Laura Snell, the director of the University of California Cooperative Extension in Modoc County, said that she started the Devil’s Garden Colt Challenge three years ago as a way to find more homes for wild horses, whose numbers have ebbed and flowed over the decades since the Wild Free-Roaming Horses and Burros Act was passed in 1971.

The law requires federal agencies to protect and manage the feral horse population, which doesn’t have natural predators, on public lands. To do that, federal land managers operate corrals similar to no-kill animal shelters in urban areas by trying to place the mustangs in good homes.

Ms. Snell said that an array of programs over roughly 30 years have sought to pair wild horses with willing trainers, including students and prison inmates. But Ms. Snell said that it was unusual for programs to allow participants to adopt the animals outright, as the colt challenge does.

By 2016, there were some 4,000 horses on the Devil’s Garden Plateau alone, an area that experts determined could sustainably support only 400.

“We’re seeing the highest numbers we’ve ever had,” Ms. Snell said. “There’s a real need to think outside the box.”

***

When the colt challenge finally arrived in June, rain intermittently sprinkled on the horses.The children whispered last-minute instructions to their mustangs, patted their noses and fed them carrots.

“I’m feeling good,” said Kati Hallmark, 14, a seasoned livestock show participant who trained a Devil’s Garden colt named Walker. “I think he is, too. His ears were forward, so he’s alert.”

Cliff Thomas, volunteering as a judge, walked the obstacle course with his grandson.

Mr. Thomas said he saw the program as a desperately needed corrective to a decline in youth participation in horse culture.

“My approach is if you can communicate with a horse, you can communicate with people,” he said.

One by one, the 19 competitors whose families were able to bring them back to Modoc County coaxed their horses around the ring.

Ben watched with a slight frown.

“I’m excited,” he said. “But I’m most nervous about the trailer — it’s a new smell.”

“If you’re confident, he’ll be confident,” his mother said. “Just be patient.”

In the ring, Mason Sedillo, a 10-year-old, led his horse, Sassy Llama, to a tarp meant to mimic a small stream. She balked.

Afterward, Mason’s best friend, Joshua Fernandez, ran up to offer solace.

“I’m so proud of you,” Joshua told Mason throwing an arm around his friend’s shoulder.

Some young trainers exited the ring teary-eyed. Kati tried several times to lead Walker through a tunnel of dangling pool noodles, clicking her tongue and quietly coaxing him, to no avail. Mr. Thomas nodded at her to move on.

“It was a learning experience, for sure,” she said later. “I worked so hard, but he put his whole entire body weight against me.”

At one point, Buddy reared back as Ben tried to urge him forward. Buddy stood stock still at the edge of the ramp into the trailer. Ben, shorter and smaller than his equine companion, took deep breaths, a frown fixing itself on his face as he tried to move an animal that would not budge.

“To see the kids with a young horse and trying to do an obstacle course is just like life,” Mr. Thomas said as the competition came to a close. “They got to see how they deal with the frustrations and the challenges.”

At the end of the day, Ms. Snell handed out awards, and no one left empty-handed. Ben joined a row of five children in his age group to accept a yellow fourth-place ribbon and a bag of Purina. His parents smiled and clapped.

The next morning, Kati woke up at her family’s sprawling ranch outside of town. The day before had been disappointing. But just like every other day, she got up and headed toward the red barn where the animals lived. She cleaned the stalls. She fed the horses. Walker munched happily on hay.