The Country Bears
Country Bear Jamboree isn't so much a ride at Disney theme parks as it is a stage show featuring animatronic bears performing country music for the audience. The show was incredibly popular in the parks, so popular in fact, that it received a "spinoff show" called The Country Bear Christmas special for the winter season in 1984. Country Bear Jamboree was a staple of the theme parks so it's no surprise that Disney decided to expand the idea into a full-length movie based on the characters. The movie was live-action with the Bears being suits created by the Jim Henson creature shop.
The movie performed poorly as well, causing a planned sequel to get canceled. It seemed like the poor performance of both Mission to Mars and The Country Bears would suggest that theme park rides aren't a good inspiration for movies, but Pirates of the Caribbean would come out the next year, changing everything.
During his lifetime, Walt Disney was fascinated with the idea of futurism, and scientific innovation, and a possible, man-made future Utopia. Some of his unrealized ideas for Epcot point to those interests, and it was those interests that really sparked the idea for Tomorrowland. The movie was originally titled 1952, but would eventually be renamed Tomorrowland to better associate itself with the Disney theme park.
After four Pirates movies, Tomorrowland was the first new Disney film to be based on anything park related in over a decade, but it was met with mixed reviews. Due to the high budget for the movie, it ended up being seen as an unsuccessful project for the studio.