High Quality Content by WIKIPEDIA articles! Rainmaker Mountain (also known as North Pioa Mountain) is the name of a mountain located near Pago Pago, American Samoa on Tutuila Island. The mountain is a volcanic feature known as a trachyte plug. This means that it is a volcanic intrusion made of extrusive igneous rocks having alkali feldspar and minor mafic minerals as the main components and a fine-grained, generally porphyritic texture. The average annual rainfall on the mountain is around 200 inches (5 m). The mountain is a National Natural Landmark designated in 1972.