Zao's Okama Crater Lake and Frost-Covered Trees — The Volcanic Lake with Spectacular Four-Season Views

Straddling the border of Miyagi and Yamagata prefectures, Mt. Zao is one of Tohoku's most dramatically varied mountain destinations — offering volcanic crater scenery in summer and autumn and the world-famous "juhyo" (frost-covered trees) spectacle in winter. The mountain's Okama Crater Lake sits at 1,758 meters elevation, its vivid emerald-green water contained within steep volcanic walls: a perfect natural jewel that changes color with weather and season, earning it the nickname "Goshiki-numa" (Five-Color Pond) for its ability to shift between green, blue-green, and deep blue.

Highlights

Okama is accessible in summer by the Zao Echo Line toll road, which climbs through alpine meadows to the crater rim viewpoint. The view of the lake, typically a deep emerald or turquoise, surrounded by the bare volcanic crater and (in early summer) patches of snow, is one of Tohoku's most striking volcanic landscapes. The Echo Line itself passes through a landscape of remarkable alpine beauty, with views across both Miyagi and Yamagata on clear days.

In winter, Zao transforms around its ski resort (one of Japan's largest) where the phenomenon of juhyo — fir trees and other conifers encased in rime ice and windblown snow into fantastic upright shapes — creates an otherworldly forest of white forms. Lit at night, the ice-covered trees resemble the "snow monsters" (yukimi dake) described in local legend.

Getting There & Tips

From Yamagata, bus to Zao Onsen in about 40 minutes. The Echo Line toll road operates May through November — check opening dates. In winter, ski resort gondolas access the juhyo viewing area.

Best Time to Visit

Summer–autumn for Okama; January–February for juhyo. The combination of onsen (hot springs) and juhyo viewing makes a winter visit particularly compelling.

📚 Sources

The Zao crater lake Okama (Goshiki-numa), its scale of about 325 meters in diameter, the Zao Echo Line and the winter snow monsters introduced in this article are organized based on tourism information published by municipalities and tourism associations including Miyagi Prefecture and Zao Town, along with operator guidance such as the Zao Echo Line and the Zao Ropeway, and on-site lookout information. The period when Okama can be seen and the snow-monster peak draw on public information from official bodies and operators. Because the Echo Line opening status and ropeway operations change with the weather, please confirm official information before you visit.

Visitor Checklist

• Time estimate: About half a day for the Okama lookout and a stroll near the summit. Allow a full day to add a bath at Zao Onsen after descending.
• What to prepare: Weather near the summit changes easily and temperatures are low, so bring an extra layer or cold-weather gear. To see the winter snow monsters, heavy cold-weather gear and non-slip footwear are essential.
• Best timing: Okama can be seen from the Echo Line opening in late April to early November. The snow monsters peak from late January to February. Fog can hide Okama, so aim for clear weather.
• Suggested route: For Okama, drive via the Echo Line from stations such as JR Shiroishi-Zao and view the mysterious crater lake from the lookout. For the winter snow monsters, take a bus from JR Yamagata Station to Zao Onsen and use the ropeway. After descending, a soak at Zao Onsen is a pleasure.

Practical Information for Your Visit

• Access hours (Zao Highline): This toll road leads to the Okama observation point and is open from 7:30 to 17:00
• Tolls (Zao Highline): 600 yen for an ordinary car, 450 yen for a motorcycle (125cc or over), 1,500 yen for a microbus or route bus, and 2,400 yen for a large bus or similar (revised April 1, 2025)
• Parking: The Zao Katta summit car park has about 350 spaces and is free of charge
• Overnight traffic restrictions (Zao Echo Line): During periods when snow or icy road surfaces are possible, the roughly 6.9 km stretch from the Sainokawara gate to the Miyagi-Yamagata prefectural border is closed daily from 17:00 to 8:00 the next morning
• Zao Ropeway (snow monsters): The Sanroku Line runs 8:30-17:00 and the Sancho Line 8:45-16:45. A round trip between Zao Sanroku Station and Jizo Sancho Station costs 4,400 yen for adults and 2,200 yen for children
• Inquiries: 0224-34-2725 (Zao Town Tourist Information Office / 9:00-17:00, open every day); for road restrictions, 0224-53-3903 (Ogawara Civil Engineering Office, Miyagi Prefecture)
• Official information: Zao Town Tourism and Products Association official website / Miyagi Prefecture official website "Notice of overnight closure of the Zao Echo Line" / Zao Ropeway official website

* The above is a guide based on information published by each facility and local authority. Hours and fees may change, so please check the official information before you set out.