Precipitous cliff + skilled skier + healthy dose of insanity + camera = awesome ski movie.

This formula may seem obvious today, when anyone with a GoPro and a lift ticket can make a ski movie. But when it was first conceived, it was revolutionary.

A pair of skis, after all, are the only thing that separates jumping off a cliff from being a good idea and a very, very bad one. And when you add a camera to the mix — "There's really something about a camera that lowers a skiers' IQ," observed the late documentary filmmaker Warren Miller — things get really nuts. The result is just so compellingly watchable.

Skiing is believed to be 10,000 years old. But it was not a true spectator sport for a very long time. It took the advent of ski movies to show people just how watchable skiing is.

This is the story of how it all changed.

Today, snow sports are a multi-billion dollar industry. It hasn't always been that way: When Warren Miller got his start in 1949, he estimates there were fewer than 15 chairlifts in all of America. Although he was far from the first to make a ski movie, Miller broke into the industry at the opportune time, when returning military service members found themselves with the money to afford ski vacations. Miller was among their number: He bought his first movie camera with his $100 Navy bonus.

Miller, who died last month at the age of 93, once described himself as having a "unique, mean-spirited sense of humor," one that was often aimed at klutzes in lift lines or those who were unfortunate enough to be caught at the rope tow by his crew. But between Miller's slapstick humor and rhapsodic philosophizing, his ultimate goal was always to inspire and motivate would-be skiers: "If you don't do it this year," he often urged, "you will be one year older when you do."

Unlike many who came before him, he had the rare gift of making something people would rather be doing into entertainment that was nearly as fun just to watch.

He was also ridiculously prolific: Warren Miller Entertainment reliably put out one ski movie a year over the course of its namesake's 67-year career. After the release of his first film, Deep and Light, in 1950, Miller spent the subsequent decades touring from city to city with his film de l'année, a sort of Pied Piper of snow sports, personally delivering a live commentary to accompany his footage. By 1960, Miller was booking screenings in more than 100 U.S. cities, and his son, Kurt Miller, estimated to The New York Times that during his father's peaks, some 300,000 people would turn out across the country to see each new film.

"Warren Miller is the man who made the snowball that created the whole industry," explained one of his hundreds of successors, Teton Gravity Research founder Dirk Collins.

The ski industry, meanwhile, was also exploding: Over the 1960s, nearly half of today's 5,500 ski areas would pop up around the world. By the mid-1970s, resorts would count some 53 million annual visits by skiers. James Bond, the epitome of cool, first skied in On Her Majesty's Secret Service in 1969, and would do so in three additional movies through A View to Kill in 1985. The sport had hit the mainstream in a big way.

"What the real catalyst for the growth of a sport is, though, no one can say for sure — though advertising and fads obviously play a large part," Ski wrote in a 1974 article on the growth of the industry. Certainly Warren Miller's films were a bit of both, featuring resorts across the world as well as the newest trends in the industry, many of which blessedly never made it off the ground. His films were, for many people, a first introduction to skiing.

Miller, though often sponsored by industry brands, saw his role as divorced from the solely commercial: "I really believe in my heart that that first turn you make on a pair of skis is your first taste of total freedom, the first time in your life that you could go anywhere that your adrenaline would let you go," he once told The Seattle Times. "And I show that in my films. I didn't preach it."

By the 1980s, through a combination of perseverance, luck, and stubbornness, Miller had cornered the market on ski movies. "Today," he brags in his 1983 film Ski Time, "there are over 237 ski shops in California and only one guy is still producing feature length ski films."

He was right. But it wouldn't last for long.

If Warren Miller was impish and grandfather-like, swaddled in his Nordic-patterned sweaters, Greg Stump was the neon, bad-boy troublemaker you wish you were as cool as, complete with a loud, infectious laugh that turns the room. "A small, muscular man, [Stump is] a glider, one of those select few who seem to not quite touch the ground, nor feel the weight of problems," as a 1989 profile in Ski put it.

A two-time national ballet skiing champion, Stump had caught the eye of another pioneering filmmaker, Dick Barrymore, and was invited to travel to New Zealand to star in Vagabond Skier in 1979. It was during the trip that Stump realized, watching Barrymore work, that a single person was capable of being his own director, cinematographer, booking agent, talent scout, and editor. After returning stateside, Stump strapped on 75 pounds of equipment, a pair of skis, and got to work making his own movie.

In order to promote it, though, Stump decided to finagle his way into Miller's latest movie: the 1983 feature Ski Time. "It was really great promotion for my name," Stump told The Week of the experience, "because it came out right when I did my first ski movie."

Miller, though, was unamused by his young rival: "I was such a pain in their f--king a--," Stump colorfully put it, which might explain why Miller would re-edit the film to change Stump's name and list his occupation as "avocado farmer."

But not even Miller could hold back the dam. Stump's fifth feature, The Blizzard of Aahhh's, in 1988, is so aggressively different than anything that had come before that it that it was almost a middle finger to Miller himself. "When I was a little runny nose kid, I would never miss a chance to watch one of Dick Barrymore's ski movies at the local ski shop," Stump says in the beginning of the film, adding: "I stopped watching ski movies quite a few years ago. Mostly because Barrymore quit making them, and I just stopped caring about the kind of ski heroes who were available."

So he made his own.

Or, rather, stole, as was the case with Scot Schmidt, a former Miller skier with a stomach-turning affinity for plunging off what appear to be sheer cliffs. Stump also reeled in handsome bump skier Mike Hattrup and, rather accidentally, the larger-than-life hard-partying, be-mohawked Glen Plake (and let's not forget Zudnick the Skiing Dog). The Inertia nicely sums up how this motley crew was received:

Remember, this was the late eighties. Reagan conservatism was in full-force; Blizzard of Aahhh's thrust freeskiing into the same category as Dogtown skateboarding and surf culture. Skiing was beginning to shed an image defined by Aspen vacationers and strict powder 8-turns. It was starting to embody one word: extreme. Miller had first ventured into displaying extreme skiing in 1984, but Stump's signature film is known as a major factor in that perception shift. And it was also responsible for inspiring a new generation of skiers. [The Inertia]

Just as music was central to skateboarding and surf culture, Stump helped make it an essential staple of the ski film, where it remains a central component today. He divorced himself from Miller's tradition of symphonic soundtracks, often picking his music — including Seal and Frankie Goes to Hollywood — before shooting, rather than the other way around. "It brought pop music into the fray," Stump told Ski in 2012. "MTV was brand-new, so this was a big deal, as the youth movement instantly became the film's audience."

While Miller continued his one-man film tour around the country, Stump got a leg up with the younger generation by seizing the opportunity presented by the exploding popularity of home VHS players. Stump released a number of groan-worthy titles that thrived on home video. (His repertoire includes Dr. Strange Glove, License to Thrill, The Good, The Rad & The Gnarly, and the fantastic Fistful of Moguls.) Most important of all, he was able to sell his VHS tapes right out of the back of his car.

"The only reason anyone knew me was word-of-mouth through VHS tapes," Stump explained to The Week. "I mean, my stuff in Europe? I have no idea how heavily it was bootlegged, or what I never received from the distributor guy."

Stump's effect on the industry was nothing less than seismic, with Blizzard having "a life-changing effect on many skiers," The Telegraph writes, including "the late ski and BASE-jumping pioneer Shane McConkey, ski mountaineer Chris Davenport, Matchstick Productions founder Steve Winter, and Corey Gavitt, the founder of Teton Gravity Research ski films."

Compare, for example, how Warren Miller shoots Chamonix in Escape to Ski in 1988 ...

... versus Greg Stump's version, the same place and year:

"Warren Miller deserves a lot of credit for getting the ski movie thing going, but it's sometimes frustrating working with his film company," Schmidt later explained in the 1989 Ski profile. "A lot of stuff I think is great ends up on the cutting room floor."

Stump had no such inhibitions. After Blizzard of Aahhh's, Scot Schmidt and Glen Plake were invited on the Today show in an effort to explain what seemed like certifiable insanity. Throughout the segment, host Bryant Gumbel is barely able to pick his jaw up off the ground. "How often are you afraid when you do this?" he asks. "Do you do everything to the extreme?"

At home, many Americans who had never watched skiing outside of the Olympics were wondering the same. Just like that, extreme had transformed from being just another adjective to a lifestyle. "'Extreme' was really an unknown word then, but once Blizzard came out, you could get an extreme combo at Taco Bell," Stump told CNN.

(NBC's Today via Legend of Aahhh's)

In his exceptional film looking back at his own impact on the industry, Legend of Aahhh's, Stump explains that "we weren't just rebelling against the state of the American ski industry and the ski areas. We were rebelling against the status quo of the American ski film." Miller may have extended warm, welcoming arms to skiers of all abilities, but Stump gave them something to dream of. Most of us will never jump off a cliff, but watching Stump's films, one wonders, briefly and with a thrill, what that rush might feel like.

Stump eventually stopped making ski films for the same reason his mentor Barrymore did: "Someone was going to get hurt, or worse." As he told Skiing in 2008: "I just don't want to film the crazy s--t anymore. I don't want to be responsible for any tragedy." And as Legend of Aahhh's movingly shows, the tragedies would come.

Today, as in the 1980s, ski films are often sponsored by brands, running budgets of between $500,000 and $1.5 million. While Warren Miller Entertainment still relies on tours (screening in almost 300 locations in 2015), the relatively niche market means the films tend to gross only about a few hundred thousand to a few million dollars. "It's not a great business model," admitted Murray Weis, an executive producer with Matchstick Productions, to The New York Times. "It's a fun business model."

And for the faithful, it remains irresistible. The spectacle of skiing keeps pulling us back — back to the stories, the adventures, the cliffs, the characters. It stirs something in the soul that even Stump isn't too cool for.

"Sweet freedom," Stump calls it in Legend of Aahhh's. "Warren Miller certainly has that one right."