Zao Onsen was first discovered 1,900 years ago by Kibi Tagayu, who served in the army during the Japanese military expedition to the east by the Japanese warrior Takemikoto. In the Edo period (1603-1867), it became a busy western trailhead to Zao Gongen, and already had the appearance of a comprehensive resort. In the Taisho era (1912-1926), a road connecting the villages at the foot of the mountain to the hot springs was opened, and various facilities such as streetlights and a police station were installed, thus establishing a foothold as a tourist destination. In the Showa Period (1926-1989), ski resorts were opened, ropeways were installed, and sightseeing roads were opened, further establishing Zao as a tourist destination. In parallel with these developments, hotels, pensions, and guest houses opened one after another, in addition to the traditional ryokan inns. Zao has developed into one of the largest comprehensive mountain resorts in the Tohoku region.