LATE last summer when Shaun White, the two-time Olympic gold medal snowboarder and X-Games superstar, was charged with public intoxication and vandalism, he became at age 26 an accidental metaphor for his sport: a young phenom all grown up, and in a spot of trouble.

After exploding onto the scene about two decades ago, snowboarding is now sputtering in the United States, according to a recent study by RRC Associates, which tracks trends that affect the winter-resort industry. “Today, there is every indication that the growth in snowboarding we took for granted has stalled, and visitation from snowboarding is headed toward a path of substantial decline,” Nate Fristoe, RRC Associates’ director of operations, wrote in the National Ski Areas Association Journal.

For several months now, Mr. Fristoe’s report has been the buzz of the industry. For some it’s also become a rallying cry to revive this sport, which, with its bad-boy image, was widely credited with saving a dull and moribund ski industry in the early 1990s.

From just 7.7 percent of all visits to American ski slopes two decades ago, snowboarders accounted for nearly one-third of visitors two years ago. Now that surge has fizzled. The percentage of visits to resorts by snowboarders even declined slightly each of the last two seasons, to 30.2 percent last winter, according to a survey by the National Ski Areas Association. The average number of days that snowboarders — usually a more hard-core bunch than skiers — hit the slopes also has seen a “sharp drop” from 7.6 days a year at its height 15 years ago, to 6.1 today, Mr. Fristoe wrote. Meanwhile the average number of days that skiers went to the mountains has remained consistent at about 5.5 days for several years.