On Christmas morning 1965, Sherm Poppen bound together a pair of discount-store skis and created what became known as the Snurfer, combining elements of skateboarding, surfing and slalom water skiing to invent a smooth-riding precursor to the snowboard.

“I lived on the shore of Lake Michigan, and I’d always wished I could surf,” Mr. Poppen later told Snow magazine. That day, “I looked at the snow on the dunes behind my house and it dawned on me that we had a permanent wave right there.”

Over the next decade and a half, more than 750,000 Snurfers — a portmanteau of snow and surf, with no relation to the blue, mushroom-dwelling Smurfs — were sold nationwide. Historians credit Mr. Poppen’s invention with spurring the development of snowboarding, a sport that nets hundreds of millions of dollars in annual merchandise sales and is featured at the Winter X Games and Olympics.

Mr. Poppen, who never became wealthy from the invention, had little interest in launching a sport or business empire when he used a piece of floor molding to screw skis together in his garage. Instead, his work was driven by a desire to entertain his 5- and 10-year-old daughters — and to keep them out of their Muskegon, Mich., house while Mr. Poppen’s pregnant wife rested inside.

“When I saw how much fun the kids had Christmas Day,” he later told the journal Skiing Heritage in 2008, “I spent the next week in Goodwill and everywhere else buying up every water ski I could find.”

Mr. Poppen was 89 when he died July 31 at his home in Griffin, Ga., where he had lived for about a decade, ever since declining health forced him off the slopes. The cause was complications of a stroke, his family said.

“I saw it as a children’s toy, really — something to play in the backyard and replace the sled,” Mr. Poppen told the FNRad Snowboarding Podcast in 2015 . “Because every year a few people died on sleds by running into trees headfirst. This way, they could stand up, jump off and jump back on, and save their head.”

In a phone interview, his family recalled that Mr. Poppen named the toy at the suggestion of his wife and continued to update it with help from his father, who proposed adding a rope to the front to help riders steer and hold on to the board after falls. “He’s not known for following directions,” his daughter Julie Poppen said. “He always drilled a million unnecessary holes in everything.”

By March 1966, Mr. Poppen had applied for a patent for his “surf-type snow ski,” which featured a board that was wider and shorter than a normal snow ski, topped with “antiskid foot treads” to prevent riders’ boots from slipping. The toy was licensed to the Brunswick Corp., an Illinois-based bowling company that placed it in the Sears catalogue in time for Christmas. Early models sold for $6.88.

Three Chicago-area friends, Vern Wicklund and brothers Harvey and Gunnar Burgeson, had patented another proto-snowboard, a modified sled known as a “bunker,” in the 1930s. Mr. Poppen’s Snurfer was the first to be mass-produced, although the marketing campaign was such a failure it inspired a Harvard Business School case study. Advertisements declared “Snurf’s the word!” But it was unclear whether “Snurfing” was a sport or a children’s game, like twirling with a hula hoop.

Still, the Snurfer made its way to future snowboard innovators, including Jeff Grell, Chris Sanders and Bob Weber, and Mr. Poppen helped organize Snurfing competitions in Muskegon. Tinkerers such as Tom Sims and Dimitrije Milovich developed hands-free models in the wake of Mr. Poppen’s creation. And Jake Burton Carpenter, who received a Snurfer at 14 and soon launched his own company, Burton Snowboards, helped popularize the modern snowboard and bring it to mountains across the country.

“I always felt there was an opportunity for it to be better marketed, for serious technology to be applied to it, so Snurfing could become a legitimate sport instead of a cheap toy,” Burton told Sports Illustrated in 1997. “I knew there was an opportunity there. I couldn’t believe Brunswick never took advantage of it.”

Mr. Poppen, who devoted most of his career to running an industrial-gas supply company, generally seemed unbothered that his creation became successful only after others developed it further.

“It was Jake’s perseverance that got us on the chairlift,” he told a Steamboat Springs, Colo., newspaper in 2009. “Otherwise [snowboarders] would still be hiking up the hill.” Burton, he later told FNRad, “saw a future that frankly I dreamed about but didn’t think was possible.”

Sherman Robert Poppen was born in Muskegon on March 25, 1930. His father was a lawyer and the city’s attorney, and his mother was a school principal turned homemaker.

Mr. Poppen studied business at Northwestern University and, after graduating, served as a supply officer in the Navy. He eventually returned to Muskegon, where he joined Lake Welding Supply and became its owner.

In the mid-1990s, he retired and sold the company to his employees through a stock-ownership program that was “one of his biggest points of pride,” his daughter Wendy Poppen said in a phone interview.

He was also delighted by the exhibition of early Snurfers at the Smithsonian’s National Museum of American History, which holds his papers, and the construction of a 14-foot Muskegon sculpture, “The Turning Point,” that charts the development of snowboarding. At the top stands a young Snurfer rider modeled after Mr. Poppen’s two oldest daughters.

His first wife, the former Nancy Bazarnick, died in 1993. Survivors include his wife, the former Louise Kelly of Griffin; three daughters, Wendy of Fort Collins, Colo., Laurie of Shelby, Mich., and Julie of Boulder, Colo.; a stepson, Patrick Kelly of Concord, Ga.; a sister; and five grandchildren.

A devoted skier, Mr. Poppen started snowboarding only in his mid-60s, after he said he grew tired of speaking at snowboard conferences where he was the only person without a board. He was also a competitive sailor and served on the planning commission in Norton Shores, a Muskegon suburb where the family moved soon after he invented the Snurfer.

“Right when it was invented, Julie was being born,” Wendy said, offering one explanation for why Mr. Poppen never devoted his career to the Snurfer. “They were designing this new house in Norton Estates, and my dad was really putting his neck out for this house. He had three kids now. I’m sure he was terrified financially to put all his time into this dream thing — he just had to keep working.”