With a height of 1841 meters, Mount Zao is one of the most prominent mountains in the Tohoku Region, sitting on the border between Yamagata and Miyagi Prefectures. The active volcano features a beautiful crater with lake, known as Okama (御釜) due to its resemblance with a traditional cooking pot. The crater cannot be approached but viewed from a distance outside of winter.
A spectacular road, the Zao Echo Line, leads to close to one of Mount Zao's secondary peaks, called Kattadake (1758 meters), before descending the mountain on the other side into Miyagi Prefecture. From Kattadake, tourists can view the Okama Crater without much effort, and there is also a shrine, visitor center and restaurant. It is also possible to hike from Kattadake to Zao's highest peak in about 45 minutes, from where it takes an additional 45 minutes to reach the upper station of the Zao Ropeway which descends to Zao Onsen.
Outside winter (late April to early November), cars can drive along the Zao Echo Line to a parking lot just below the Kattadake peak. The last few hundred meters to the parking lot are a toll road that costs 550 yen per car (round trip). Alternatively, there is a free parking lot a few minutes drive further down the mountain, which is connected with the Kattadake peak by a chair lift (750 yen round trip).
One bus per day runs on weekends and holidays from late April through July and daily from August to early November from Yamagata Station via Zao Onsen to the Kattadake peak and back. The one way trip from Yamagata Station takes about 90 minutes and costs 2050 yen. From Zao Onsen it takes about one hour and costs 1470 yen.
Alternatively, there are two buses per day between Kaminoyama Onsen Station on the Yamagata Shinkansen and the Kattadake peak outside of winter. The one way trip takes about one hour and is free of charge! Note that the bus does not pass through Zao Onsen.
Lastly, the Kattadake peak can also be reached from the Miyagi side by one daily bus from Shiroishi Zao Station along the Tohoku Shinkansen on weekends and public holidays between late April and early November. The one way trip takes around 1.5 hours and costs 1960 yen. The buses also stop at Shiroishi Station along the Tohoku Main Line.
It is also possible to take the Zao Ropeway from Zao Onsen to its upper station (1500 yen one way, 3000 yen round trip) and walk from there for about 45 minutes further up the mountain to the summit of Mount Zao from where the Okama Crater comes into visibility.