At the height of the nation’s snowboard craze, Rod Rice was a so-called blazin’ raisin — an older dude who loved to bomb the slopes at breakneck speeds.

That is, until he wiped out and dislocated his shoulder on a trip to Canada. The 65-year-old engineer still loves to carve fresh powder, but now he does it on a pair of extra-wide skis.

“I’m not planning on going back to snowboarding,” said the Lakewood, Calif., grandfather.

Once the king of the mountain, snowboarding is on the down slope.

The rage that transformed the nation’s ski resorts and planted such terms as “jib,” “face plant” and “biff” into America’s lexicon is cooling off partly because many older riders are shifting to new, easier-to-ride skis to preserve their aging bodies.

Sales of snowboards and snowboard equipment have slipped 21 percent over the last four years, while sales of skis have climbed 3 percent in the same period, according to SnowSports Industries America, a trade group that tracks the $3.5-billion snow sports and apparel industry.

Baby boomers aren’t the only ones bailing. Last season, alpine skiing replaced snowboarding as the most popular snow sport among kids ages 6 to 17, according to the trade group. That’s the first time in nearly a decade and a troubling sign for snowboard makers battling for a key demographic.

The once-hip, ultra-extreme sport may have lost its lure when mom and dad began snowboarding a few years ago.

“Kids don’t want to do what their parents do,” said Chris Riddle, a spokesman for Snow Summit and Bear Mountain ski resorts near Big Bear Lake. He said he’s seen an increase in skiers in the terrain park typically dominated by snowboarders.

A snow-loving member of the millennial generation, 17-year-old Arten Yegikyan from La Crescenta, Calif., tried snowboarding on Bear Mountain a few months ago. He said he gave it up because he felt beat up and frustrated when he was done.

“It felt like you had no control over the direction you are going,” said Yegikyan, who now prefers skiing.

The limitations snowboarders face in powder and flat terrain are a reason Kristy Chocholaty, 35, of Truckee, Calif., has given up on the sport. She jumped on the snowboard bandwagon in the late 1990s. “I wanted to check it out because so many people were snowboarding at the time,” she said.

But she said she gets frustrated when she tries to keep up with her skier husband and gets stuck in places that he can simply push through with his poles.

Ski and snowboard manufacturers acknowledge these factors. But they predict sales will rise again as manufacturers push new board designs that will make them easier and safer to ride.

Meanwhile, new ski designs are making it easier for ski fans of all ages to enjoy the sport. Thanks to so-called shaped skis, many beginners are gaining proficiency quickly, while some veterans are mastering tricks that would have been difficult on conventional skis.

Shaped skis are shorter than traditional straight skis. They’re also wider at the front and back. That hourglass shape enables skiers to turn with less effort — and with fewer wipeouts. These wider skis are also better for schussing over powder and cruddy snow. Plus, skis with upturned tips on both ends can be ridden forward and backward, just like a snowboard.

As a result, powder hounds who want to try downhill skiing, backcountry trekking and terrain park tricks can do it all and save money by buying one set of skis.

Thanks to such new designs, skiers will compete for the first time in slopestyle and half pipe competitions at the 2014 Winter Games, the International Olympic Committee recently ruled.

“It’s interesting where the industry is going now,” said Josh Holm, who manages the ski rental shop at Squaw Valley Ski Resort. “You can ski on a half pipe and land backward just like a snowboarder.”

Modern snowboarding was invented in the 1960s, but most ski resorts refused to let riders on their slopes until the 1990s, when the sport’s popularity began to boom. Snowboarders made their debut in the Winter Olympics in 1998, and by 2004 they outnumbered skiers on U.S. slopes.

From 1990 to 2004, the number of Americans who participated in snowboarding jumped about 340 percent, from 1.5 million to 6.6 million, according to the National Sporting Goods Association. In the same period, the number of skiers dropped 48 percent, from 11.4 million to 5.9 million, the trade group said.

Since 2004, however, snowboard participation has dropped 22 percent while skiing has climbed 16 percent, according to the trade group.

Another factor in the decline of snowboard sales may be that many new riders are beating themselves up trying to perform the stunts and tricks executed by snowboard superstars.

A 2012 study by the University of Vermont College of Medicine concluded that snowboarders have a higher injury rate than skiers. Snowboarders tend to suffer more injuries to their wrists, shoulders and ankles as well as concussions, while skiers had more knee and lower leg injuries, according to the study.