ट्रिविया

This was the final Thomas and Friends production to use an all model set. The twelfth season aired with several parts of the set in CGI, and starting with Thomas & Friends: Hero of the Rails (2009), all footage was done in CGI.

Shown in selected theaters in the U.S. throughout July, in the UK throughout September, and in Australia throughout November of 2008.

Pierce Brosnan was to take over as narrator starting with this special, but after HiT Entertainment announced its plans to switch to CGI, his status was changed to "special guest narrator".

In Japanese releases, this runs under the name of "Mystery Mountain".

Originally Gwyneth Paltrow was going to be the narrator but the role went to Pierce Brosnan instead.