Miyagi · Mt. ZaoNo.584★★★Open in map →

Okama Crater Lake

— The Zao volcano's green summit pool

natureThe classic — done right

A round volcanic lake on the ridge of the Zao range in Miyagi, its water turning green, blue or white as the light moves. The mountain road that reaches it opens only from late spring to the start of winter.

FromYamagata Station (Yamagata Shinkansen)
~95 minSeasonal bus, one a day
Okama Crater Lake

Directions ↗

Where it is

23 more notes in Miyagi · open the map →

What to look for — in walking order

The Okama viewpointOKJaguar / CC BY-SA 4.0

Komakusadairaa lookout on the Echo Line below the summit, named for the alpine flower on the scree
Zao Sancho Rest Housethe building at the head of the Highline where the bus and the car park arrive
The Okama viewpointa railed terrace a short walk above the car park, looking straight down into the crater
Kattadake summit and its shrinethe peak on the southern rim, with a shrine that predates the road by centuries
The crater rim paththe ridge route north toward Kumanodake, the lake on one side, under volcanic advisory

How to actually get there

Yamagata Shinkansen to Yamagata Station.
Yamagata Station → Kattadake summit on the seasonal bus, about 95 minutes, one run a day.
From the car park, walk up to the crater viewpoint and on to the shrine on Kattadake.
Return to the car park in good time for the single bus back down.

Seasonal summit bus from Yamagata Station: In season a bus runs from Yamagata Station up to the Kattadake summit, taking about 95 minutes and going once a day. It is the one public service that puts you on the crater rim without a car. On the Miyagi side a Miyako Bus service also reaches Zao Kattasancho, on weekends and holidays only and likewise once a day.
Down from the summit: The same bus is your way down, and with a single run a day there is no second chance if you miss it. Build the visit around the return departure and leave a margin for cloud, which can slow the walk back along the rim.

Directions from my location (Google Maps) ↗

About the place

Okama lies in a crater on the ridge of the Zao range, inside a national forest in Zao town, Miyagi, with the Yamagata border running just to the west. The pool measures about 325 metres across in either direction and roughly 1,080 metres around, and the water reaches 27.6 metres at its deepest. Colour is what people come for: sunlight and the state of the volcano turn the surface green, blue or a milky white, and that is why the lake also carries the name Goshiki-numa, the pond of five colours. The water is strongly acidic. Nothing lives in it.

How to enjoy it

The bus that reaches the summit runs once a day in season, so the day is built around it rather than the other way round; check the return departure before you walk away from the car park. Cloud closes over the crater without warning even in midsummer, which makes a clear hour something to use rather than to save for later. The rest house keeps summer hours only, from nine in the morning to late afternoon.

Background & history

Zao is a live volcano, and the bowl that holds Okama is a late feature on a range people had already been climbing for centuries as a place of worship — a shrine still stands on the Kattadake summit above the present car park. For most of that history the lake was something you walked up to over a long day. That changed when the Zao Echo Line was cut across the range and the Zao Highline was built to climb the last stretch to the top. Both close for the winter, which is why a famous view has an opening date at all.

Before you go

Cash: There is no admission to the crater or to the viewpoint, and the summit car park is free. Vehicles do pay a toll on the Zao Highline, the spur road that climbs the last stretch to the top.
Good to know: The Zao Echo Line and the Zao Highline close for the winter, roughly from early November to late April, and while they are shut the crater cannot be reached at all. The rest house keeps summer hours only. Above the tree line the air is far colder than in the valley in any season, and the official advice is to bring a layer you can add and shoes that hold on loose ground. Zao is an active volcano under continuous monitoring, and the town asks visitors to keep out of the Uma-no-se caldera inside the designated crater zone; check the alert in force before you set out.
Another way: From the Miyagi side the approach is the Zao Echo Line up from Togatta Onsen, with the Murata or Shiroishi interchange on the Tohoku Expressway about an hour below. Walkers can also come over the ridge from the Jizo Sancho station of the Zao Ropeway, an hour and a half to two hours one way.
After you get off: The rail leg ends at Yamagata Station and the summit bus leaves from the stands outside it; everything above that is mountain road. At the top the bus and the cars share one car park, and the crater viewpoint is a short walk up from it.