Artist Proof of pin 57790. Released at Walt Disney World October 2007. Join Chip and Dale as they journey to the top of the Forbidden Mountain in this Open Edition pin released as part of the Mystery pin Collection. They are playing in the yeti footprint in the snow. Have a blast with the gang as they enjoy some of the popular Walt Disney World® Resort Attractions in this Open Edition Mystery Pin Collection. Each box contains two (2) randomly selected collector pins on a specially designed backer card. AP stamped on back.