The misty_mountains_ins.zip file you have requested: Maps / Singleplayer / The Misty Mountains - 615.05kb is not available. Perhaps try browsing all files for the game Battle for Middle-earth and upload any files you want to share or are missing. This is the only information we could locate:
Notes from author - SwanknightYou are Gandalf and you are passing through the Misty Mountains. You must find the right passage out but beware of the unfriendly armies of foes waiting to spring out on unwary travelers, but there are some friendly allies in certain places which can be a big help. Enjoy!