On either side of a viewing ramp, the pens at the Central Oregon Livestock Auction are a slow-moving sea of lumbering cattle.

In a nearby enclosure, a lonely mare attracts the attention of Chris Buller and four of his young Rez Riders. They peer over the railing at what looks to be a healthy and sweet-tempered animal.

Buller, 40, makes it a practice of coming each week to this stockyard in Madras to shop for old horses nobody wants. Funds for his 3-year-old horse-focused nonprofit organization — Faith Trails of the Rez Riders and Sanctuary — are limited but with them he buys horses, trains young people to ride and care for them, and often resells the animals to families with beginning riders.

Many horses that end up at the regular Wednesday morning bargain hour were once loved and ridden by children who grew up and moved away, Buller explains. Eventually, the families tire of caring for them.

Typically, that happens during winter months when there’s nothing for animals to graze.

“Hay’s really expensive this year, especially,” Buller says. “A lot of great horses just don’t make it.”

In Madras and at other auction yards, old, saddle-ready horses are bought on the cheap and transported to slaughterhouses in Washington and Canada for pet food or products overseas.

Hiram Yaw Jr., 12, was selected, along with three high school girls, to join Buller on this last-minute field trip to the stockyard. Buller works part time as a substitute teacher in Jefferson County schools and keeps careful tabs there on kids in his program. Hiram, or “Junior,” as his mother calls him, has made outstanding progress and is on the honor roll for the first time.

Hiram, a Warm Springs resident, has been through a lot in his young life, explains his mother, Pamela McDermott. There was a divorce, she says; the father who once pampered him is no longer in the picture. Then the child’s grandmother died. And McDermott, who suffers from severe rheumatoid arthritis, says she cannot keep up with her three kids.

But since falling under Buller’s wing a year ago, she says, “he’s really changed a lot.” He’s happier, she says, “and his attitude has improved; he has more respect for people.”

McDermott likes the fact that she and other family members are invited along to every Rez Riders event, training session and gathering.

Hiram’s eyes linger on the mare in the pen. Buller says he will pass the horse over in search of a gelding, but the freckled, wiry boy looks on for a few extra moments. Finally, he leaves the railing and joins his Pied Piper-like mentor, who is striding toward the auction arena, his charges following close behind.

The sights and sounds of the auction leave Buller’s crew speechless.

“It’s like something you see in the movies,” Mariah Rodriguez, 16, finally manages to say.

An auctioneer’s singing staccato and the animals’ regular complaints hypnotize the kids. Buller, who fits right in among the booted, hatted men around him, takes notice of his newcomers’ wide-eyed expressions, and he smiles.

Success in school is key, he says, but this field trip is a learning experience, too.

“It’s important that they see what a big part of the economy this is, right here in Madras,” he says.

More lessons are in store.

Buller’s 30 or so regular riders will have the chance to help run the Ikiutan Stables at the Kah-Nee-Ta High Desert Resort on Warm Springs, starting this summer. Buller, who leases two small ranch areas, one on and the other adjacent to the reservation, will embark on a new enterprise with his kids at the resort.

The Rez Riders, Buller says, will help him clean up the existing stalls and build additional ones for guests who bring their own horses to ride on the reservation.

They will also build a new round pen and arena.

Buller hopes to have his kids running nearly everything. They will man the cash register, keep the books, lead trail-riding groups and carry on conversations with the customers.

“I’m trying to teach them to network,” he says. “They need to know how an entrepreneur thinks.”

He estimates that with tips, the kids could make up to $10 an hour. They will get a free meal every day that they work and will be allowed access to the resort’s swimming pool.

“They’ll get exposed through this to all kinds of people,” Buller says.

A week after the field trip to the auction yard, Buller finds what he is looking for — a horse around 15 years old, with a calm temperament. He won her with a $208 bid — nearly the same amount his kids raised at a hot dog sale in Redmond the day before.

“She would have been just dollars on hooves,” he says of “Roja,” who was destined for the slaughterhouse. “But now she’ll be happy, and the kids will love her.”