Skiers and patrol members stand on a slope at the Jeongseon Alpine Centre. (Yelim Lee/AFP/Getty Images)

Shortly after Christmas, Tom Johnston, a soft-spoken Wyoming cowboy, will leave his sprawling ranch, saying goodbye to his wife, his cows and his quiet, solitary life. He will make the 20-hour trek to South Korea, where he will spend the next two months caring for a mountain, tending to its curves and its bumps.

Johnston is a snow guru and is tasked with readying the Alpine racecourse at the PyeongChang Olympics, a simplistically complicated job that means Johnston is essential but far from the spotlight, just the way he prefers. He carries the nondescript title “chief of race for ski events” and has been prepping for the Winter Games for more than two years. These next two months, he figures to spend every day, from sunup until past sundown, making sure every inch of the course is prepared for the world’s best skiers.

“You just go as hard as you can and look at every little spot that isn’t perfect,” he explained in a recent interview. “My hayfields are the same way — I want them to be perfect.”

The job isn’t simply moving snow to and fro. It’s bringing the mountain to life. The Pyeong­Chang course was designed by Bernhard Russi, who was an Olympic gold medalist in the downhill at the 1972 Games. Johnston was essentially given a blueprint and charged with molding the terrain and crafting the jumps.

The key is the snow, and the job is more of a scientific undertaking than a snow-shoveling chore.

Tom Johnston stands near the finish area following a men's World Cup super-G race at the Jeongseon Alpine Centre during a test event last year. (Andrew Dampf/AP)

“Tommy is a magician with snow,” said Steven Nyman, an American skier and three-time Olympian.

Johnston, 55, laughs at the suggestion, but the skiers on the World Cup circuit know the difference between a course that Johnston tended and all the others.

“He knows how to put in the time it takes to make the snow good. There’s no excuses with him,” said skier Travis Ganong, who’s aiming for his second Olympics. “He just makes it happen no matter what. That’s why he’s the best in the business. Every course he’s always done, it’s way better than everywhere else we go.”

While Johnston will use a team of helpers and a fleet of large snowcats to move snow, the challenge is understanding the snow at a molecular level and the ever-changing weather. He wants a course that’s fast but not dangerous, which requires constant supervision and attention to the smallest details.

“The crystal structures in the snow, you look at it and think, ‘Can I change that?’ ” he explained. “ ‘Will adding water make it worse? If I use a snowcat on it, will it make it better? Are the nights cold? Will the sky be open or closed? What’s the humidity?’ ”

Snowflakes might look like perfect crystals under a microscope, but they can make for lousy puzzle pieces at times. Johnston prefers cold conditions with the perfect amount of moisture. He wants snow that sticks, that’s malleable, that can be moved. And then there’s this: One of the world’s authorities on snow also happens to hate when it actually snows.

“I don’t like natural snow. You can’t control it,” he said, noting that he prefers the man-made variety that can be blasted out of guns positioned all along his racecourses.

“You got to build a course that’s durable. You got to guarantee the product,” he continued. “If it falls apart, then they hate you. But they seem to hate you less if it’s icy.”

Even if the course is pristine on the eve of the Olympics, all it takes is an overnight flurry or a morning gust to wreak havoc on his frozen canvas.

“When the weather’s good, you’re a hero,” Johnston said. “I’ve had some good luck with weather.”

“He’s a weather junkie,” noted his wife, Cassy.

On cue, Johnston pulled out his iPhone and opened a weather app, on which he can monitor the weather in a dozen places — including Copper Mountain, Colo.; Killington, Vt.; Sun Valley, Idaho; and South Korea’s Gangwon province, where the Olympic Alpine races will take place — always aware of how the conditions are impacting the courses he builds and maintains.

“Our lives are controlled by the weather,” his wife joked. “And he doesn’t just listen to what the weatherman says — he’ll try to predict it on his own.”

While some European resorts hire specialists with scientific backgrounds, Johnston is an English major from Whitman College in Walla Walla, Wash. He took up skiing as a child and raced throughout high school and college. He started coaching after college, which is how he got started crafting the courses and preparing the snow, eventually serving as the chief of race at Jackson Hole (Wyo.).

But all that time, ski racing and snow mostly were a means to pay the bills. It’s a passion, he said, but it’s not like cattle ranching.

“Every year I was like, 10 more cows and I won’t have to coach anymore,” Johnston said.

Although he’s traveling to different ski resorts for much of the fall and winter, cattle ranching is still a full-time job, and the Johnstons have 85 cows and about three dozen calves on their property in Pinedale, Wyo., a small town in the western part of the state.

He attacks both pursuits with the same enthusiasm and work ethic. Whether he’s on the ranch or on the mountain, he’s out before dawn each day and often doesn’t return until after 10 p.m. “There’s no ‘recreation’ in his vocabulary,” his wife said. “He just works.”

“You can see how that ranching background has made him really meticulous and such a hard worker,” Ganong said. “He just puts in the time, and it takes time to get the track perfect.”

The TV cameras might not capture the subtleties of the mountain, but the racers certainly notice. While the men and women will race on the same course in PyeongChang, four years ago at the Sochi Games, Johnston was responsible only for the women’s course.

“We were looking at that, like, ‘Oh, man!’ and then our hill was just a sheet of ice,” Nyman said. “It was so gnarly. We were like, I wish Tommy was preparing our hill. But he’s doing this one for the Olympics, and it’s going to be fantastic. I’m pretty fired up.”

Johnston has prepped the Olympic hill for two test events, tweaking and massaging the course along the way. The mountain is never fully ready until the first racer starts down the course, and Johnston is planning to spend every waking hour between Christmas and the start of the PyeongChang Games in February making sure every snowflake on the course is perfect — even better than nature intended.