BIG LAKE, ALASKA – When Morgan Martens, 14, stepped off his sled at the Junior Iditarod finish line after 16 hours, 40 minutes, 20 seconds of mushing, his grin was barely visible beneath his warm layers.

His winning time aside, he had completed a feat that few 14-year-olds attempt: leading a team of 10 sled dogs on a two-day race of nearly 150 miles through the Alaskan wilderness.

The Junior Iditarod, the longest race in Alaska for competitors younger than 18, is a chance for young mushers to demonstrate an unusual set of skills. They need to know how to steer a sled, use survival equipment, brave the icy winds and avoid hypothermia.

They need to know how to navigate the course, and what to do if they get caught in a snowdrift or if the trail disappears. They need to know their dogs well, too: Which ones prefer fish over beef? Do their feet need bootees, or is the weather too warm?

Ten mushers ages 14 to 17 accepted the challenge on a recent Saturday morning, a week before this year's Iditarod. Alaskan Dallas Seavey made history Monday by capturing his fifth championship in the 852-mile race.

The junior mushers started at Knik Lake, an hour's drive north of Anchorage, and wound their way over 75 miles to a remote lodge, where they camped overnight amid windchills that went as low as single digits. After a mandatory 10-hour stopover, they mushed some 65 miles to the finish line at Big Lake.

Anna Coke, a 17-year-old musher, has been mushing for years.

She said she was inspired by watching the Iditarod as a child.

"When I was 10, I was like, 'I'm going to pray every night that I would become a musher,' " she said.

Two years later, she formed a friendship with Jessica Klejka, a veteran Iditarod musher, and has been training with her since. Coke takes daily trips from her home in nearby Wasilla to Klejka's kennel in Knik and practically lives there in February, spending all of her free time caring for the dogs and going on training runs.

She has run Klejka's dogs in the junior race for the past three years.

"Nothing in the entire world can beat being out alone with your dogs, with your team," Coke said. "It brings you a lot of peace. And they push you to become a better person through that. They're relying on you and you're relying on them. It's a really, really beautiful picture of teamwork and endurance and hard work."

Many junior mushers train for years to make it to race day, and friends and family come out to support them at the start line before they embark on their two-day journey.

"There's a lot of work behind the scenes," Coke said. "As high school students, everyone mushing in the Junior, it's a very, very big time commitment."

For some participants, the event would be the first time they spent a night away from their parents.

Most of the competitors in the junior race were born into the sport. Ava Moore Smyth, 14, of Willow, is a third-generation musher: Both of her parents have run the Iditarod, her grandfather ran the first Iditarod, and her grandmother was one of the first female mushers to finish the race.

Ellen Redington, 14, from Knik, is a fourth-generation musher. Her great-grandfather Joe Redington Sr. was known as the founding father of the Iditarod, and her parents met on the Junior Iditarod in 1991.

Martens, this year's winner, was the only entrant not from Alaska. But the sport runs in his family. His mother, Janet Martens, competes in 20- to 40-mile races near the family's farm in Brule, Wis.

Morgan Martens has the support of his classmates back home, too.

"The principal sent out an e-mail, so my entire school is going to be watching," he said.

The Junior Iditarod has been run since 1978, just five years after the first Iditarod. The race is supported by sponsors, which help provide the prizes: The winner receives a new dog sled, a beaver fur hat and musher mittens. There is also a $6,000 scholarship.

Before embarking on the two-day journey, each musher loaded emergency gear and each dog was evaluated by a veterinarian. While there are adults on the course, including a race marshal on a snowmobile, the young athletes also have satellite trackers for their safety.

The GPS tracker provided a measure of reassurance for Janet Martens. Though her older child, Talia, raced the Junior Iditarod in 2018, she was still worried about what Morgan would experience overnight.

"Will he get hypothermia from running all day, you know, 75 miles? Will he be all sweaty and get cold?" she said. "Will he eat the food I sent with him or is he going to eat all the candy?"

Her fears were put to rest when her son crossed the finish line.

"I think he took a step up into more of an adult perspective as far as thinking about what he has to do and what responsibilities he has," she said. "There's 10 dogs that depend on him, and he took it very seriously. So as far as that goes, he's learned a lot of adult skills most adults don't have."

All of the mushers finished safely, some persevering through more than 20 hours on the trail. They faced icy winds, snowdrifts, disappearing trails and the occasional moose.

"It teaches them confidence and ability to take things that you don't foresee happening and figuring it out, not only for yourself, but you have a team of dogs," said Julia Redington, a Junior Iditarod board member and Ellen Redington's mother.

"They are all competitive, but it's also about the journey and just what they learn."