Minutes before kickoff of Boise State’s season-opening game against Washington on Sept. 4, two A-10 Warthog fighter jets roared past Albertsons Stadium.

A loud music video introducing the Boise State team played on the big screen, and smoke was fired out of the tunnel from which the players were about to emerge. Large university flags were waved, and fireworks were shot into the air. It was sensory overload.

At the back of the north end zone, a 19-year-old mare named Shyann stood facing away from the spectacle. Her owner, Beth Miller, Boise State’s Bronco Girl, tried to remain calm in the saddle. But the circuslike atmosphere made this an impossible task.

“When we’re going out there, you can feel her getting excited,” Miller said. “You can really feel her heart beat. And it gets my heart racing, too.”

Finally, it was time to take off. The horse turned around and raced toward the 50-yard line. The announced crowd of 36,836 — the Broncos’ second biggest ever — was in a frenzy as Miller and Shyann sped down the field, with Beth carrying a large flag bearing Boise State’s logo.

Seconds later, the team took the field, and Shyann headed back toward the north end zone and out of the stadium. Having done their job riling up the fans, Miller and Shyann disappeared as quickly as they had come.

Miller, a Boise State junior who is in her third year as the Bronco Girl, said riding Shyann required her full concentration, somewhat reducing her ability to enjoy the experience. Still, Miller would not dream of being anywhere else at the start of Boise State home games.

“It’s kind of a blur,” Miller, 30, said. “I’m so focused on my horse that I don’t take it in as much as I should.”

The equine mascot tradition at Boise State began in 1965, when the institution was known as Boise College. That season, a horse named Spyieche was charged with running a lap around the field after every Broncos score.

It is hard to fathom that Shyann would be able to handle such a workload, given Boise State’s potent offensive attack. Luckily for the mare, she is called on to run only once a game.

Shyann, a dark liver chestnut Morgan, is not terribly imposing, standing at 15 hands. She is playful and has a friendly demeanor. Miller quickly became attached to Shyann on her family’s farm in Marsing, Idaho.

“I grew up with her, bonded with her,” Miller said. “If you ever asked me, ‘What horse do I trust with my life?’ It’s this one.”

The two were nearly separated when Shyann was a weanling. Miller’s parents initially wanted to sell the horse, but Miller protested. Only 11 at the time, she got a job delivering newspapers so that she could keep Shyann.

“She had a paper route for a year to pay for that horse,” Miller’s father, Michael Ferrell, said.

Miller has carried that work ethic into adulthood. In addition to her duties as Bronco Girl — which, along with the games, include public appearances — Miller is majoring in psychology and also works at a call center as a customer service representative for a bank in Meridian, Idaho.

Miller lives in Meridian with her husband, Dan, a graduate student at Boise State. She is considering graduate school, which would keep her eligible for the role, one that allows her to spend time with the horse she fell in love with as a child.

Before they head out onto Boise’s famous blue field, Miller and Shyann spend a few quiet moments together in a fenced-off staging area just outside the stadium. The night of the season opener, the fence was left open, and a Washington fan named Hayden Thomas walked through. He carefully approached the mare.

“I was told I could get a picture with the bronco,” Thomas said. “Is that OK?”

Miller happily obliged. Here, finally, was her chance to soak in the experience.

“Wait!” she said, pulling out her cellphone. “Can I get a picture, too?”