The Battle of Piva Forks, also known as the Battle of Numa–Numa Trail, was an engagement that took place during the Bougainville campaign in World War II. Occurring between 18 and 25 November 1943 on Bougainville Island in the South Pacific, the battle involved troops from the United States Marine Corps and the United States Army fighting against Imperial Japanese Army forces and took place amidst the context of the expansion of a beachhead that US forces had established around Torokina on the western side of the island.