What Is Zao Okama Crater Lake?
Zao Okama (Okama Crater Lake) is a crater lake in the Zaō Mountain Range, located in Zao Town (Katta District), Miyagi Prefecture, and is known for its mysterious, emerald-green water.
Surrounded by three peaks—Mount Katta (Katta-dake), Mount Kumano (Kumano-dake), and Mount Goshiki (Goshiki-dake)—the crater lake measures about 1,080 m in circumference, about 325 m across east to west, and reaches a maximum depth of about 27.6 m, with water colors that shift depending on sunlight and weather.
Zao Okama sits at a high elevation of around 1,670 m, and its sweeping 360° views make it a popular scenic destination.
From fresh summer greenery to vibrant autumn foliage, the scenery changes dramatically with the seasons, and the area becomes especially lively when the Zao Echo Line is open.
Another big draw is the easy drive access via the Zao Echo Line and Zao Highline, a well-developed mountain route that makes visiting by car convenient.
In this guide, we’ll cover the highlights of Zao Okama, the best ways to enjoy it, and practical access tips for travelers!
Top Things to See at Zao Okama
1. The Emerald-Green, Mysterious Crater Lake
The biggest appeal of Zao Okama is its emerald-green surface.
The crater lake is said to be strongly acidic, which is also why fish and other wildlife have difficulty living in it.
It’s also fascinating how the water subtly changes color—deep green, blue, emerald green, turquoise blue, and more—depending on the sun and weather.
On clear days, the lake shines in especially vivid green, making it an incredibly photogenic view.
That said, the high elevation means the weather can change quickly, and some days the lake may be hidden by fog or clouds.
To improve your chances, it’s best to visit with extra time in your schedule so you can adapt to changing conditions.
2. Viewpoints Where You Can Overlook Okama
Around Okama, there are several viewpoints that let you admire the crater lake from different angles.
Recommended Viewpoints
- Mount Katta (Katta-dake) Summit Observatory
- → A popular spot with wide-open views of Okama. The Okumiya (inner shrine) of Katta Mine Shrine is also near the summit.
- Viewpoint Near the Zao Summit Rest House
- → Just a short walk from the parking area at the end of the Zao Highline. With shops and restaurants nearby, it’s an easy stop.
3. Enjoy Stunning Scenery in Every Season
Zao Okama looks different throughout the year, so there’s always something to see during the open season.
Spring (Late April–June): Snowmelt and the Snow Corridor
Because of the high altitude, snow often remains even in spring, creating a striking contrast between the snowy landscape and the emerald-green lake.
The snow walls along the Echo Line (the “Snow Corridor”) are especially impressive around Golden Week, soon after the road opens, and you can drive between towering snowbanks.
Summer (July–August): Refreshing Highland Views
This season often brings clear air, and many days when the lake’s color looks especially vivid.
It’s also a great time to enjoy hiking while feeling the cool highland breeze.
Temperatures near the summit can be lower than in the lowlands, so don’t forget to pack a warm layer.
Autumn (Late September–Mid October): A Top Foliage Viewpoint
The Zao mountains turn into a spectacular autumn scene, with slopes colored in brilliant reds and yellows.
Traffic can be heavy on weekends and during peak foliage, so an early-morning visit is recommended.
Winter (Early November–Late April): Roads Closed
In winter, the Zao Echo Line and Zao Highline are closed, so you can’t reach Okama directly.
However, Zao’s famous winter attraction—juhyō (snow monsters)—can be enjoyed on the Yamagata side via the Zao Ropeway.
Combining it with skiing or snowboarding is also a great option.
How to Enjoy Zao Okama
1. Drive the Zao Echo Line and Zao Highline
From the Miyagi side, the most common way to reach Zao Okama is by taking the Zao Echo Line and the Zao Highline.
The Zao Echo Line is a mountain road that typically opens from late April to early November, letting you head toward the summit while enjoying changing scenery along the way.
From Katta Pass—the highest point on the Echo Line—you can branch onto the Zao Highline (toll road) to reach the Katta Summit Parking Area, which is close to the Okama viewpoint.
With multiple scenic stops along the route, the drive itself is part of the experience.
2. Enjoy Hiking Around Zao
There are also well-maintained hiking trails around Okama, so you can enjoy the crater lake while walking through the great outdoors.
Recommended Routes
- Mount Katta (Katta-dake) Hiking Course (about 20 minutes one way)
- → A beginner-friendly route that reaches the summit from the parking area in a relatively short time. The Okumiya of Katta Mine Shrine is also a highlight.
- Mount Kumano (Kumano-dake) Trek (about 2 hours round trip)
- → A route where you can enjoy views of Okama from the ridgeline above.
3. What to Wear and Bring
Because the area around Okama is at high elevation, it can get chilly even in summer.
Be sure to bring warm clothing and a windbreaker.
Some areas have uneven footing, so comfortable sneakers or hiking shoes are recommended.
And since weather can change suddenly, don’t forget rain gear as well.
Practical Info for Travelers
Access
By Train and Bus
- From the Sendai area, take JR to the Shiroishi / Shiroishi-Zao area
- From Shiroishi / Shiroishi-Zao, continue toward the summit by car/taxi or by seasonal bus service
By Car
- About 1–2 hours by car from central Sendai
- About 1 hour by car from Shiroishi IC (Tohoku Expressway)
- Parking available
Admission and Road Fees
- Okama viewing: Free
- Zao Echo Line: Free to drive
- Zao Highline: Toll road (fees vary by vehicle type and season)
- Typical open season: Late April–early November (closed in winter)
Wi-Fi and Mobile Coverage
- Mobile reception near the summit can be unstable, so it’s a good idea to confirm your route in advance
Summary
Zao Okama is a must-see scenic spot where you can enjoy a mysterious emerald-green crater lake and breathtaking mountain panoramas.
On clear days, the view is unforgettable, and pairing it with a drive on the Zao Echo Line and Zao Highline—or a hike around the summit—makes for an excellent trip.
Be sure to experience the grand scenery of Zao Okama for yourself!
