The Yellow Forest route features tons of Pikachu, including special ones.
Nintendo announced that the Yellow Forest Pokéwalker route is available as of April 1 in Pokémon HeartGold and SoulSilver.
The exclusive route features an array of Pikachus, some of which know Surf or Fly, and will be available until May 5.
Players can download the route by selecting Mystery Gift on the main menu. For more detailed instructions, check out the official website.