Skiing, a sport that began on steep, granite-flecked trails covered by natural snow, served by hang-on-for-dear-life tow ropes, has evolved. It’s not your grandparents’ scene anymore – and thank goodness for that.

“You think about what skiers used to have to do,” the chairman of the National Ski Areas Association, David Crowley, said the other day. “Look at the goggles and gloves and boots and skis people used to use, and you just wonder what kind of person would stick to a sport like that. They hiked up, they had to sidestep the trail in order to pack it, they had to fill in their sitzmark, and if they got in four runs a day, they thought they were doing well.”

Even skiers now middle-aged who took up the sport in college remember a different world. Lifts were slow and unreliable, snow was mostly natural and unpredictable, and seasons were limited by the whims of weather.

Of all the changes, Mr. Crowley points to snowmaking as the one driving all others. It was invented – accidentally – in the winter of 1951-52 when Larchmont Engineering of Lexington, Mass., was searching for a way to protect Florida citrus from frost by increasing humidity, thereby lowering the effective freezing temperature. Instead, they wound up making snow. (Joseph Tropeano, son of the owner of Larchmont who developed the process, said his father was initially upset. “He had funding from Minute Maid to develop a way to protect the crop from freezing, and his idea was a total failure. It turned into a success only when the news media filmed the snow because there was no natural snow anywhere in New England that winter.”)

For the ski industry, “snowmaking was the big one,” Mr. Crowley said. “Without it, we’d run 10 days a year. Instead, we operate 130.”

Without the long season, areas couldn’t spend money on lifts, trails, lodges, and all the amenities that have transformed the activity.

Mr. Crowley’s family runs Wachusett Mountain Ski Area in Princeton, Mass. Though modest in size (1,000 feet of vertical, 20 trails, and six lifts), Wachusett is one of the top 10 most visited ski areas in the Northeast. That puts it in the company of giants like Killington, Okemo, and Stratton in Vermont; Sunday River in Maine, and Bretton Woods in New Hampshire.

That’s because in skiing, as with many things, it’s all about location. Wachusett is within an hour’s drive of 5 million people.

When skiing took off in the 1930s in New England, it served far fewer people, in part because of the rudimentary technology. The development of rope tows marked the beginning of the sport’s expansion. The first one in North America is commemorated on a historic marker that reads: “Woodstock, Vermont. Site of First Ski Tow in the United States. In January, 1934, on this pasture hill of Clinton Gilbert’s farm an endless-rope tow, powered by a Model ‘T’ Ford engine, hauled skiers uphill for the first time. This ingenious contraption launched a new era in winter sports.”

The rope tow did haul skiers uphill at a good clip but required strong arms and a sure grip. When tows first came along, they were an improvement on walking uphill or sidestepping on skis to pack the runs. T-bars came next and were fabulous innovations. Chairlifts were luxurious, even the old wooden one and two-seaters that crawled uphill at a snail’s pace.

Ski areas today offer high-speed lifts (quads or six-packs), state-of-the-art snowmaking and grooming, an array of terrain, and opulent lodges, private homes, and hotels. These amenities are expensive: In the winter of 2003-04, according to the NSAA’s End of Season survey, American ski areas spent $263 million on skiing facilities and real estate. Last winter, they spent $366 million, and this season, a projected $528 million. And enormous sums were required to modernize old ski areas such as Okemo, founded in 1955, and Sunday River, which began operating in 1959. During the 1970s and 1980s, many smaller, older areas – including Mittersill in Franconia, N.H., which operated from 1945 until the early ’80s, and Mount Watatic in Ashby, Mass., which was open from the 1930s until 1983 – couldn’t come up with the money to improve facilities and, unable to compete for skiers, were forced to close. The New England Lost Ski Areas Project lists 558 ski areas that once operated in the six New England states and are now closed. Another 43 closed in New York. In New Jersey, three are closed and just a few remain.

Of more interest to skiers today are those areas that did survive the transition from the early, rough-and-tumble years. The National Ski Areas Association lists 84 ski areas operating in New England, 50 in New York, and 35 in Pennsylvania. There are 491 major ski areas operating in America.

The economic imperative is undeniable: Either show the folks a good time or suffer as skiers go elsewhere. The competition is fierce for attention from the almost 12 million skiers and snowboarders who hit the slopes a combined 57 million times last season in America. (And their lift tickets aren’t cheap: The average adult weekend ticket price last season was $56.55 in the Northeast and $64.54 in the Rocky Mountains. Of course, few people pay full price, given various season passes, lift-and-lodging packages, lesson deals, and two-day tickets.)

Ski areas also use new technology to advertise, offering special promotions on their Web sites. Almost every area has one now, with trail maps, lift ticket prices, lodging information, directions, services, and photos. Maine, New Hampshire, and Vermont also have ski area associations: www.skimaine.com, www.skinh.com, and www.skivermont.com.

The creator of American Skiing Company, Les Otten, was one of the prime innovators in the move to modernize the ski industry.

At one time, ASC’s far-flung holdings comprised areas in six states. They included Attitash Ski Resort in New Hampshire, Sugarbush in Vermont, and Steamboat in Colorado. ASC’s rapid expansion across America may have been too much, too quickly. The company ran into a combination of bad weather and tough economy, with the fortunes of each resort affecting the success of the others. Gems like Sunday River wound up supporting the operation of less profitable areas like Killington.

ASC’s fiscal implosion in the late 1990s is seen by some as a cautionary tale of where rapid modernization of ski areas and investment in real estate can lead. Others see it as bad luck with the weather. Meanwhile, a retrenched ASC continues to be a major player on the American ski scene.

Mr. Otten believes that the ski industry is not for the faint of heart and that the sport’s fundamental allure is personal challenge. “Skiing in general has an almost limitless supply of new potential enthusiasts,” he said. “The ski industry has to market the excitement of physically challenging yourself. Skiing is one of the few sports where you can risk your imagination against reality. If you can sell that idea, the industry will grow significantly.”

Though retired from the business, he still loves the sport. “Skiing is now my hobby. I’ve skied 50 days a year for the last four or five years, and I’m finding out how much fun it is. I’m finding out that I was right all those years.”

Mr. Crowley agrees that the challenge of skiing is its primary lure and one of its main virtues, despite the impressive technological improvements of the last few decades.

“The sport remains one where you’re left alone with your own devices to get down the hill,” he said. “It’s not an amusement park ride. It’s you controlling yourself and watching out for yourself and others around you. It’s a sport of personal responsibility, a bit of a throwback sport.”

Mr. Leo, a member of the Eastern Ski Writers Association, has been a ski writer for 25 years.