Six years before Mickey Mouse made his debut in "Steamboat Willie," there was "Little Red Riding Hood" -- Walt Disney's first animated work, a seven-minute silent cartoon that the 21-year-old completed while struggling as a commercial artist in Kansas City.

It was 1922 and the beginning of Disney's dream to make films that would tell stories and compete in the growing animation industry.

Though it is documented in various Disney biographies and histories, "Little Red Riding Hood" has long been considered a lost treasure. For decades nobody knew where Disney's first attempt at animated storytelling was -- or even if any prints existed.

But earlier this summer, the Disney Studio was given access to the rarity by a British collector, who had years ago quite accidentally stumbled upon the reel in a London film library and purchased it for about $3.

The Disney company now possesses a copy of the priceless cultural artifact -- which in 1980 was included on the American Film Institute list of "10 Most Wanted Films for Archival Preservation" -- and has just finished restoring this missing link to its past.

"It's a very exciting discovery of an example of Walt Disney's own animation, which is extremely rare," said historian and filmmaker John Canemaker, the author of "Before the Animation Begins: The Art and Lives of Disney Inspirational Sketch Artists." "It's also our first chance to see the origins of what would become the Disney empire and style."

No one knows how "Little Red Riding Hood," unseen in America for decades, ended up in Britain. The story of its rediscovery began in the late 1980s, when British film historian and collector David Wyatt came across the fairy tale, along with a silent short of "Cinderella" that Disney had completed about a year later, in a sale of 16mm prints from an old rental library in central London.

"They showed me this huge room full of 16mm films, and I went quietly bananas," Wyatt recalled. "I don't think I realized the films were rare, but the fact that they were titles from Disney made them interesting."

Wyatt says he didn't realize he had bought two lost pieces of animation history until he met film scholar Russell Merritt in the early '90s, who was at work on "Walt in Wonderland: The Silent Films of Walt Disney."

Disney has performed state-of-the-art preservation work on the copy, returning the original print to Wyatt. Serious collectors concerned with preserving rare films often allow archives to make copies, ensuring the film's survival.

The studio has not announced plans to publicly screen or release the film, though it is reportedly considering several possibilities.

The monetary value of the discovery is hard to pin down, collectors and animation experts say. "It could have some value," says the Burbank-based animation art dealer Howard Lowery, "if it were packaged as part of a Disney retrospective that was intended to be historical, rather than entertainment."

A typical early '20s cartoon, "Little Red Riding Hood" is more interesting for what it anticipates than what it is. Little Red's mother makes doughnuts to take to Grandma while a cat (who looks suspiciously like the already famous Felix) shoots the holes into them. Red goes to Grandma's house in a cart pushed by her little dog; on the way, she meets the Wolf. Grandma has left a note reading "gone to the movies," so the Wolf sneaks into her house and waylays Red. A dashing aviator, summoned by her dog, rescues her.

Although most of the animation is rudimentary, the film contains a few ambitious touches, such as having a character walk away from the camera in perspective. A daisy does a comic shimmy dance, probably animated by Ub Iwerks, a close friend and fellow animator of Disney's who later collaborated on the design of Mickey Mouse.

After its completion, Disney quit his job as a commercial artist and persuaded local investors to put up $15,000 to start Laugh-O-Gram Films. Disney and collaborators made five more cartoons based on fairy tales, but failed to interest a national distributor. In 1923, Disney bankrupted the fledgling studio producing his first live action/animation combination, "Alice's Wonderland." He left Kansas City to join his older brother, Roy, in Los Angeles, where he made a series of "Alice" comedies; in 1928 he created Mickey Mouse.