Avalanche on Mt Mitahara in Myoko kills a backcountry skier

A summary of public reports, written by Ski in Sky and checked against each source. It is not an official investigation, and it may change as investigations continue.

What happened

A party of four went into the mountains to ski and ride. One was carried by an avalanche and fully buried. Companions found them quickly, but they were unconscious. A police helicopter took them to hospital, where they were pronounced dead. JAN records one person caught and transceivers carried.

JAN gives the date only. A search summary put the slide shortly before 13:00, but that could not be tied to an opened source.

Where

Outside the ski areaMt Mitahara (三田原山), Myoko city; JAN gives elevation 2,300 m, east aspect. Backcountry terrain above the Myoko ski areas, outside any resort.

Known only to the area.

Link to the ski area

Near a ski area, not inside it

JAN and news describe it as backcountry (山岳 / バックカントリー) on Mt Mitahara. Mitahara is commonly reached from the top of Myoko Suginohara, but no source opened says this party started there, so it is not attributed to a resort.

People

Died1

Injured0

Rescued—Not reported

What is known about the cause

Investigation reportHuman-triggered dry slab avalanche on a persistent weak layer (facets) over a melt-freeze crust, size 2; crown 100 m wide, 20-80 cm deep; ran 195 m vertical over 360 m (JAN field investigation and press material). ^[1]
Investigation reportTransceivers carried; victim fully buried (JAN). ^[1]

Not confirmed

The time of the avalanche.
Whether the party reached Mt Mitahara from a resort lift (e.g. Myoko Suginohara).
Reports differ on the companions' details; not needed for this record.
Cause of death asphyxiation (police, reported) (reported by Joetsu Town Journal; that source could not be re-checked).

Sources

Last checked against the sources on 2026-10-22.

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