Fiore, who underwent heart surgery in 2004 and had a stroke in May, died Tuesday in a Fresno nursing home, said his daughter, Cindy Volpa.
The Canadian-born Fiore is said to have taught more than 100,000 people to ski at Badger Pass, one of California's top ski and snowboard resorts for families.
Dubbed "the maitre d' of ski at Badger Pass" by one reporter, Fiore was known as much for his heavy French Canadian accent and friendly grin as for his passion for skiing and knowledge of the Sierra.
"Nic is the magnet that draws people back generation after generation," then-Yosemite Park Superintendent Jack Morehead told The Times in 1988.
Fiore, who was executive director of the western division of the Professional Ski Instructors of America for nearly 30 years, began teaching skiing in Yosemite in 1948.
He directed Yosemite's Ski & Snowboard School at the Badger Pass ski area for 45 years before assuming the role of "ski ambassador" in 2001.
The ebullient octogenarian continued to hit the slopes nearly every day and teach an occasional ski lesson into the 2003-04 season.
"That he was able to stay in this profession and do what he loved to do for so many years was definitely an inspiration to so many of us," David Achey, president of the western division of the Professional Ski Instructors of America, told The Times in 2004.
"Our vision as an organization is inspiring lifelong passion for the mountain experience, and Nic truly lived that vision," he said.
Marek Warszawski, a Fresno Bee reporter who skied with Fiore, told The Times in 2004 that Fiore "was the smoothest skier on the hill, well into his 80s."
Many ski instructors who worked with Fiore over the years -- known as Fiore's "disciples" -- went on to lead their own ski schools, Warszawski said.
As a member of the newly formed California Ski Instructors Assn. in the late 1940s, Fiore was concerned about the quality and consistency of ski teachers in this country and advocated the creation of a national ski instructors association. The Professional Ski Instructors of America was founded in 1961.
Fiore remained vigilant in pushing the national organization to maintain high standards for the certification of ski instructors, John Armstrong, president of the Professional Ski Instructors of America and director of corporate training at Mammoth Mountain, told The Times in 2004.
On the personal side, Armstrong said, "You couldn't hope for a more entertaining, kind and caring person to spend the whole day out on a mountain than Nic. Even if you were having trouble with snow or it was a stormy day, Nic was a cheerful and upbeat kind of man; he'd inspire you to stay out all day in a blizzard."
But Fiore didn't just teach ski technique, Armstrong said; he also was a "guide."
"He'd talk to people about the mountains he had hiked to in the summer," Armstrong said. "He knew the Sierra very well, and he'd talk about the animals, geology, vegetation and what it was like to go hiking way out there. He was just a great resource of knowledge."
One of 12 children, Nicholas Fiore was born Dec. 1, 1920, in Montreal. After serving in the Canadian Army during World War II, he abandoned his dream of becoming a championship European bike racer and taught skiing in the Laurentian Mountains north of Montreal. Invited to become a ski instructor at Badger Pass by then-ski school director Luggi Foeger, Fiore drove into Yosemite Valley for the first time on the night of Dec. 8, 1947.
A heavy snow storm had obscured Yosemite's spectacular landscape, and when Fiore woke up the next morning, he reportedly gazed in disbelief at the park's towering granite walls. "This is fantastic!" he recalled saying. "But where in the world do the beginners learn to ski?"
He had planned to stay four months at the Badger Pass ski area, located above the valley floor beyond Glacier Point.
"After skiing here two days I was not even certain I wanted to stay the winter," Fiore told The Times in 1988. "I thought I would be happier on a bigger mountain." But, he said, "Deep down, Yosemite made such an impact on me. I fell in love with the place."
As one ski season moved into another, Fiore became involved in various operations in Yosemite. While teaching skiing in the winter, he worked summers in the park's hotels, including serving as maitre d'hotel of the Ahwahnee and managing the Glacier Point Lodge and the Wawona Hotel.
Fiore was named director of the Badger Pass Ski School in 1956, and in 1963 he also began managing Yosemite's five High Sierra camps in the wilderness back country.
Among his various honors, Fiore received the prestigious Charlie Proctor Award in 1986 from the Sierra Chapter of the North American Ski Journalists Assn. in recognition for his outstanding contributions to the sport of skiing in Northern California and Nevada.
When Fiore's health problems caused him to miss the opening of the Badger Pass ski resort's 70th season in December 2004, his Yosemite colleagues called his absence the "end of an era."
"Nic Fiore is an institution, and he is as much a part of Badger Pass as the buildings and the slopes," Badger Pass operations manager Colin Baldock told The Times in 2004. "He's maybe not here, but he's definitely here in spirit."
Fiore's wife, Midge, died in 2003. In addition to his daughter Cindy, he is survived by his other daughter, Nicole Goc; and eight grandchildren.