Highlights of Zao
Zao is the collective name for the mountains of the Ōu Mountain Range, which spans Yamagata and Miyagi prefectures. The Yamagata side is also called Yamagata Zao, while the Miyagi side is called Miyagi Zao.
The highest peak of the Zao Mountains is Mount Kumano-dake, with Zao-san Shrine standing at the summit in Yamagata Prefecture.
The landscape is characterized by terrain formed through volcanic activity. In particular, the emerald-green crater lake Okama in Miyagi Prefecture is an iconic symbol of Zao.
At the foot of the mountain are hot spring resorts such as Zao Onsen (Yamagata Prefecture) and Togatta Onsen (Miyagi Prefecture).
In winter, you can enjoy winter sports such as skiing and snowboarding. When the weather conditions are right, snow monsters (Yamagata and Miyagi prefectures) form, creating a fantastical scene.
Zao Onsen and the Snow Monsters
From the Torikabuto Observatory, you can look out over the foothills on the Yamagata Prefecture side. Zao Onsen spreads out in the foreground, with the Kaminoyama Basin beyond.
I visited in late autumn, but the area around the summit was covered in snow.
The phenomenon in which supercooled droplets from fog or clouds are blown onto trees and other surfaces, where they freeze and form white ice crystals, is known as snow monsters. In Zao, the term usually evokes the enormous ice-covered trees known as ice monsters.
The flow of the wind appears in a visible form.
Zaozan Shrine
The highest peak of the Zao Mountains is Mount Kumano-dake, standing at 1841 meters and located on the Yamagata side. Zao-san Shrine stands at the summit of Mount Kumano-dake. Frost-covered trees also form on its torii gate.
Zao Daigongen is said to have been enshrined on Mount Kumano by En no Ozunu after being brought from Mount Kinpusen in Yoshino, Nara Prefecture, marking the founding of the site.
At the summit of Mount Katta-dake on the Miyagi side, the inner shrine of Katta Mine Shrine stands at an elevation of 1758 meters.
Okama
The emerald-green crater lake filling the crater of Mount Goshikidake is called Okama. The color of the water’s surface changes depending on the weather and light.
It is a scene from another world. Once you cross a certain line, you feel as though you may never be able to return.
Basic Information about Zao
The information below was checked against official sources on September 16, 2026. Please also check the latest information on the official website when planning your trip.
- 🔗 Official website
- For the best time to see the snow monsters, check Yamagata Prefecture’s official tourism information. For restrictions on the Zao Echo Line leading to Okama Crater, check the official Zao Town website.
蔵王の樹氷｜観光スポット（山形市・村山地方）｜やまがたへの旅 - 山形県の公式観光・旅行情報サイト「蔵王の樹氷」は、霧状になった氷点下の水滴（過冷却水滴）を含んだ季節風がオオシラビソ（アオモリトドマツ）の木々にぶつかり瞬間的に凍り付く「着氷」と、着氷のすき間に多くの雪がとり込まれる「着雪」、そしてそれらが互いにくっついて固く絞...yamagatakanko.com蔵王エコーライン交通情報www.town.zao.miyagi.jp - 📍 Area
- This is a mountain area stretching from Zao on the Yamagata side to Zao on the Miyagi side. Check the guidance from the relevant prefecture or operator for Okama, the snow monsters, hot springs, ropeways, and mountain roads.
- 🕒 Best time and access period
- The best time to see the snow monsters is usually from late 12 to late 2. The Zao Echo Line leading to Okama Crater is closed in winter, and nighttime traffic restrictions apply immediately after it reopens. ⚠️ Snow-monster conditions, ropeway operations, and road restrictions change with the weather, so check them again on the day of your visit.
- 💶 Fees
- Entry to the Zao mountain area itself is free. Separate fees apply when using the Zao Ropeway, Zao High Line, or snow vehicle tours.
- ⏱️ Time required
- For the area around the Okama Crater viewpoint alone, allow approximately 1 to 2 hours. If you take the ropeway to see the snow monsters at Jizo Summit Station, allow 2 to 3 hours. If you also combine the visit with hiking or hot springs, allow from half a day to 1 day. ⚠️ Okama, Mount Kumanodake, Jizo Summit, and Zao Onsen are far apart, and the time required varies depending on road and ropeway conditions.
Getting to Zao
It takes about 40 minutes by car from Zao Onsen to the Zao Summit Rest House and Okama Crater Viewpoint. The route follows the Zao Echo Line (free of charge) and joins the Zao High Line (toll road) along the way. The road is closed in winter, so plan accordingly.
Another option is to take both the foothill and summit lines of the Zao Ropeway, then trek from Jizo Sancho Station to Okama, a journey of approximately 1 hours each way.
In winter, you can see the frost-covered trees by taking the Zao Ropeway from Zao Onsen or joining a snowcat tour from Mountain Field Miyagi Zao Sumikawa.
When the Zao Echo Line is open to traffic
If you are driving to Okama, the Zao Echo Line is closed for the winter every year from the beginning of 11 through the end of 4, and it may also close during the day in the open season because of icy conditions or bad weather. In 2026, access is scheduled to remain open until 11. 4 17, so check the road conditions before setting out.
The related guide “【山形】観光スポット・グルメ・交通・モデルコースを解説” is currently available only in Japanese.
