Walt Disney's original concept art for Disneyland is to be auctioned.
The hand-drawn map from 1953 shows how many of Disney's ideas came to fruition and reveals how much the park has grown since it opened in 1955.
Tomorrowland was originally going to be called World of Tomorrow, while Frontierland was Frontier Country. Lilliputian Land never became a reality and no one could have foreseen a Star Wars land opening in 2019.
Walt Disney spent a marathon weekend in 1953 brainstorming ideas for the new family amusement park he envisioned.
There would be a train station and an old-fashioned Main Street square. The park would have a princess castle and a pirate ship, maybe even a rocket.
Disney wanted to get investors on board, so he described the various elements he imagined to artist Herb Ryman, who translated them into a hand-drawn map - Disneyland's first.
That original concept art could fetch as much as one million US dollars (£770,000) when it goes up for auction next month, auctioneer Mike Van Eaton said.
Collector Ron Clark knew the map was special when he acquired it 40 years ago from a former Disney employee who had been friends with Walt Disney.
Mr Clark said he felt a "spirit of presence" as soon as he saw the ink and pencil drawing on paper.
"It had this aura," he recalled. "It just kind of puts you in awe that this is the piece that came out of Walt Disney's mind and this is what came about: this park, these parks worldwide, the passion people have for it today and the happiness of hundreds of millions who have graced these lands."
Mr Clark started collecting Disney items in the 1960s. He saw a small silver spoon in a Disneyland souvenir shop and plunked down 10 dollars for it.
When he later saw that same spoon show up as a collectors' item in a Disney fan magazine, he was hooked.
"I have an affection for the man and what he created. It's just brought us and our family such joy," said Mr Clark, who still holds an annual pass to Disneyland and makes it out to southern California from Utah at least three times a year to visit the park.
"All 20 of our grandbabies are Disney-fied," he said.
Mr Clark's collection focuses on the dawn of Disney.
The earliest piece is an Ingersoll watch from 1928 and the most spectacular is the map. But with his 70th birthday approaching, Mr Clark wanted to see about finding a more permanent home for his prized piece of memorabilia.
"It was always my desire to somehow return it to Disney," he said. "I wanted it to go home. For 40 years, that has been my wish."
Disneyland spokesman John McClintock would not say if park officials will be among the bidders when the map goes up for auction on June 25.
He was familiar with the piece, though, calling it "a very speculative drawing".
"It was drawn to make people think this is going to be a great park," he said.
Walt Disney Parks and Resorts still produce concept art for new park features.
The company released a full-colour image last year of the proposed Star Wars land, complete with an X-wing fighter flying overhead.
The 14-acre Star Wars expansion represents the biggest ever at Disneyland, Mr McClintock said, though the park has been evolving almost since it opened in 1955.
For the auctioneer, whose Van Eaton Galleries are full of Disney animation cells, old park souvenirs and even the googly-eyed sea monster from the now-shut Submarine Voyage ride, the pre-Disneyland map is "the ultimate".
After spending the past four decades locked away in a vault, the map will be on view for the public at the gallery in the weeks leading up to the auction.
"There's never been anything like it," said Van Eaton.