After the success of DISNEYLAND's Matterhorn, park management pestered Walt to build another coaster. When Walt's idea of Space Mountain proved to be ahead of its time, Walt came up with a different idea for a magical mountain adventure- Big Rock Candy Mountain. An elaborate mountain, covered with large bits of "candy" would have a high speed train racing through gumdrop caverns and lollipop forests.
Disney Legend Harriet Burns was assigned to create a model of the mountain, so she went to various candy stores and bought all the sweets she could carry. She returned to Walt Disney Imagineering and set about creating a model of the mountain as pictured below. Her workshop became a popular place as others sought to raid her candy stash. After finishing the model, she recalled that Walt spent a lot of time staring at it and came to the same conclusion she had- that it was just too much. However, he thought maybe it might look better outside in natural lighting, so they wheeled it outdoors. As soon as they stopped the cart and stood back to look at it, a huge flock of birds descended on the model and began tearing it apart, eating the candy. They all saw it as a sign that Big Rock Candy Mountain wasn't meant to be.
The mountain was obviously never built, but its train elements were used in Big Thunder Mountain Railroad years later. The area it was meant to fill (behind Storybookland and the Casey Jr. Circus Train) is now occupied by the Fantasyland Theater. A replica of Harriet's model was made from non-edible materials as a tribute and can be found across the esplanade in DISNEY CALIFORNIA ADVENTURE at the Trolley Treats Candy Shop.