Frontierland was one of the five original themed lands at Disneyland's opening. Initially, the land did not contain many attractions. It was centered around open expanses of wilderness which could be traversed by guests via stagecoach, pack mules and walking trails. It's come a long way, and now it includes attractions such as:
Big Thunder Mountain Railroad
Rafts to Tom Sawyer Island
Frontierland Shooting Exposition
Mark Twain Riverboat
Sailing Ship Columbia
Big Thunder Ranch
The Bonanza Outfitters is a great store right on the corner of Frontierland and Adventureland. Besides being gigantic, it is a great place to duck into and use as a shortcut after the Fantasmic and firework crowds.