Oirase Gorge
奥入瀬渓流40°32′ N 140°58′ EGorge
Oirase suits walkers who want a long, easy riverside walk through old forest below Lake Towada; the road runs beside the path the whole way, so weekend traffic follows you in autumn.
Photo lumoplank · Wikimedia Commons · CC0 and others, credited in the gallery
Access
The walking path runs close to the water at about the same height as the road beside it.
The Oirase stream drains Lake Towada at Nenokuchi and runs about 14 kilometres down to Yakeyama through a U-shaped valley of beech, katsura and horse chestnut. The gradient is gentle, about one metre in 70, and moss and shrubs grow on every rock and fallen trunk. A path follows the water at stream level the whole way. The road runs beside it.
The famous stretches come one after another. Ashura no Nagare is the fast, white rapid you see on posters and on TV. Kumoi Falls drops 20 metres in three steps from a side valley, and Choshi Otaki is the only waterfall on the main stream. It stands 7 metres high and 20 metres wide and kept fish from swimming up to the lake, so for a long time people said no fish could live in Lake Towada.
A water gate at Nenokuchi releases lake water into the stream by day and almost closes at night and in winter, when side streams carry most of the flow. In 2026 Aomori Prefecture tried a week with no private cars on the road beside the stream, from 7 to 13 September. Shuttle buses ran from designated car parks that week.
Worth knowing
- Go in mid-May to see murasaki-yashio azaleas flowering on the boulders at Sanran no Nagare.
- Keep to the path and stay quiet near the water. Japanese serow live in the forest here.
Quick answers about Oirase Gorgeよくある質問
How long is the Oirase Gorge walk?
The path along the stream runs about 14 kilometres from Nenokuchi on Lake Towada to Yakeyama.
What is the best season for Oirase Gorge?
Mid-May for fresh green and azaleas, autumn for colour, and winter for frozen waterfalls on guided tours.
Can you get to Oirase Gorge by bike?
Route 102 runs beside the stream. In 2026 the road between the Sobe junction and Nenokuchi, about 10 km, closed to private cars from 7 to 13 September for a trial week, and the Oirase bypass carried through traffic.
Within 12 km
