奥羽山脈
Nishiwaga is located in the far southwestern corner of Iwate Prefecture, in the river valley of the Waga River, surrounded by the 1000-meter peaks of the Ōu Mountains on three sides. The area is noted for its extremely heavy snowfall in winter. The Yuda Dam is located in Nishiwaga and the Yuda Onsenkyō Prefectural Natural Park is located completely within its borders.