The custom wax truck used by U.S. Ski and Snowboard at the 2017 Nordic World Cup in Davos, Switzerland. (Reese Brown/US Ski and Snowboard)

No U.S. woman has ever won an Olympic medal in cross-country skiing. When Jessie Diggins finished fifth in the skiathlon this week, it was the best Olympic finish by an American woman ever.

Until then, the American best had been Sophie Caldwell’s sixth-place finish in the sprint at the Sochi Olympics. Before that, it was Kikkan Randall’s eighth-place finish in the same event in Vancouver in 2010. Little by little, Olympic cycle by Olympic cycle, the American women have been kicking and gliding their way toward an Olympic arrival. From their perspective, they’re finally ready to arrive in style.

In December, through a massive fundraising effort and with the help of U.S. Ski and Snowboard, the American women bought a state-of-the-art wax truck that follows them to World Cup competitions.

They couldn’t bring the truck to the games in PyeongChang, in large part due to time constraints and shipping costs. The team needs the truck in Finland the week after the Games, and the cost of shipping from Europe, right back to Europe, was more than they could bear. Most other teams, including the Norwegians, could not bring their trucks to Pyeong­Chang, either.

But the team did bring the confidence the truck helped them build.

“We’ve had consistently great skis all season,” Randall said. “. . . Then it’s also just the feeling of when your truck is parked among all the other trucks, you really feel like you’ve arrived. Now we show up, we pop out the sides, and it’s like, ‘All right, we’re here to compete.’ ”

Seven of the 11 U.S. skiers at the Games have medaled on the World Cup Circuit. Three of them have won there. This season, five different U.S. skiers medaled on the World Cup tour. In the four years before this one, the high was three.

One reason for the breakthrough is hard work — the progress that can only be made by persistence over time. Another is the push made by leaders such as Randall, a five-time Olympian, to earn more support from the governing body and entice more young skiers to follow their paths. Another major factor, all of them say, is the truck.

Elite cross-country competitors rely heavily on wax technicians to prepare their skis. U.S. assistant coach Jason Cork estimated that the difference between the best- and worst-prepared skis can equate to as much as 50 seconds over a 16-minute race, and most races are much longer than that. When Norway’s powerful cross-country team struggled to medal in Sochi four years ago, skiers and media blamed the wax technicians.

The way a ski is prepared can affect its ability to grip and glide, and in both classic and skate skiing the ideal preparation shifts depending on temperature, humidity and other factors. Preparing skis to match conditions requires hours of testing and ski preparation, as well as keeping a wide range of skis in tow.

Until this season, the U.S. team’s technicians would pack 25 or so 200-pound boxes, drive them to the next stop on the World Cup tour, rent trailers or cabins to work out of, unload the boxes, then pack them all up again when the competition ended.

The techs would be at the mercy of whatever ventilation those rental facilities provided. The wax and powder used on elite skis contain fluorocarbons, dangerous toxins often found in aerosol products.

In 2008, top cross-country countries such as Norway and Sweden began buying and outfitting their own wax trucks. By outfitting a truck specifically to carry gear, they saved their techs hours of work. By customizing their trucks, they improved ventilation to mitigate the risks faced by their staffs. Plus, arriving at competitions in custom trucks painted with team colors just added to their clout.

“It felt like you were more than just an underdog. It felt like you were competing in a different situation,” said American skier Sadie Bjornsen, who is competing in her second Olympics. “We’d always get a laugh out of it when the Norwegians would say, ‘We have bad skis today.’ We kind of wanted to say, ‘Welcome to the world.’ ”

Randall started snapping pictures of rival trucks in 2012, hoping to entice U.S. Ski and Snowboard to get one. Two years ago, she was able to speak to U.S. Ski and Snowboard’s board of trustees and explain why the truck would make a difference.

“All of a sudden you could see in their eyes — ‘Whoa, you guys really are up against a lot,’ ” Randall said. “And I never wanted to see that money and resources was making the difference, but we’ve all worked incredibly hard and we’ve gotten incredibly far, and now it’s those small little things that really matter.”

U.S. Ski and Snowboard chipped in, while skiing fans raised more than $600,000, according to the governing body’s website. The truck debuted in November, just as the American women began their most successful cross-country season to date.

“I definitely think our strike rate has gotten even higher,” Diggins said. “I’ve always been so proud of our staff. . . . I think our rate of just nailing it more and more consistently and having extremely competitive skis — that’s getting even better.”

While they do not have their truck in PyeongChang, skiers and staff alike rely on the results they say it helped them achieve this season to motivate them during the Games.

“I think it’s certainly been magic this year,” Bjornsen said. “I always wish we could bring the technicians up on the podium with us because they’re more than 50 percent of our success.”