In 1969, Disneyland and Coca-Cola teamed up for the Discover Disneyland sweepstakes. Participants collected specially marked coke bottle caps. An illustration of Sleeping Beauty's castle was displayed on the top of the cap along with the Coke logo (although some variants have been found without the castle). The underside featured a character or attraction that you would see at the park. Snow White and Dopey were paired together.
The collected bottle caps (or plastic liners) were to be affixed to a special game sheet--a map of Disneyland with 35 blank circles. There were different level prizes awarded dependent upon the number of completed sheets submitted. The top prize for five sheets included a free adult admission to the theme park and a ticket ride book!
One facebook individual shares his memories as a kid, running all over town searching for the caps in order to win free tickets to Disneyland: read here.