Bighorn is a town near the coast of Drum Island. The town is a little closer to the Drum Rockies.
When Wapol returned, he ate many of the buildings, and it was later engulfed in an avalanche. After Wapol's defeat and the Straw Hats' departure, the citizens of the town (led by the newly elected king, Dalton) went to work, digging it out. When the Straw Hats' new bounties were posted after the Enies Lobby incident, Dalton called Kureha down from the castle to Bighorn tell her about Tony Tony Chopper's bounty.
One Piece Manga and Anime — Vol. 15
Chapter 133 and Episode 80.
One Piece Manga — Vol. 26
Chapter 243, cover story: Wapol's Omnivorous Hurrah Vol. 7,
Dalton and the citizens digging out Bighorn.
One Piece Manga and Anime — Vol. 45
Chapter 440 and Episode 324,
Dalton shown at Bighorn to informing Dr. Kureha of Chopper's newly issued bounty.