In The Hobbit, Bilbo, Gandalf and a party of dwarves cross the Misty Mountains and are captured there by a band of goblins. After he escapes into the deeper caves, Bilbo finds Gollum and the One Ring.
In The Lord of the Rings, the Fellowship attempts to cross over the mountains, but is foiled by Saruman. They are forced to go through the Mines of Moria instead.
The Lord of the Rings Online
The Misty Mountains are the main questing area for Book 5, with a level range in the early to mid 40's. The game area also contains two major instances, one of which serves as the largest raid in the game. Goblin-Town, located in the north east corner of the region, serves as a reputation dungeon, while Helegrod (in the far northern area) is the game's largest raid, a 24-man raid that culminates in a battle with Thorog, the undead dragon from Book 5, Chapter 8.
Gloin, father of Gimli, is a quest-giver and NPC in the area.
The Misty Mountains are unique in that there are no transportation options throughout the entire region.