O-osawa-koya (Ōsawa-goya)

0261-22-1584

☎️

0261-22-1584 ☎️

O-osawa-koya (Ōsawa-goya / 大沢小屋) is a small, historic mountain hut on the classic approach from Ogizawa (Kurobe Alpine Route area) toward Harinoki Pass and Mt. Harinoki-dake. It’s best understood as a relay hut—a practical stop that supports early starts, breaks up the ascent, and provides shelter before the steeper, more committing upper terrain.

• Hut Overview

  • Location: Ōsawa-deai (Ōsawa junction) on the Ogizawa → Harinoki route, Northern Japanese Alps

  • Altitude: ~1,675–1,680 m (directories differ slightly)

  • Type: Mountain hut + small tent site

  • Capacity: commonly listed as 20 people (some listings show 30)

  • Season: typically early July to early September (varies year to year)

  • Notes: often requires reservation; operated in coordination with Harinoki hut in the same area

• Access & Approaches

  • Main approach: Ogizawa → Ōsawa-goya (lower section of the Harinoki Pass route)

  • Typical hiking time: about ~1 hour from Ogizawa (common planning reference)

  • Difficulty: T2 (trail hiking), but conditions can change quickly with rain and runoff in the valley.

• Facilities & Comfort

  Simple, functional facilities aimed at short stops and early departures:

  • Sleeping dormitory (no private rooms)

  • Water available, but drinking conditions can be affected after heavy rain (plan to fill earlier at reliable springs when advised locally)

  • Toilets available

  • Tent site: listings vary; often described as very limited (2–3 tents)

• Food & Atmosphere

  Expect a quiet, operational atmosphere: most guests are either breaking up the approach to Harinoki Pass or staging for an early push into the snow valley/upper ridge in stable weather windows.

• Routes & Alpine Context

  O-osawa-koya is primarily used for:

  • Staging the climb toward Harinoki Pass / Mt. Harinoki-dake

  • Managing the effort before the more serious upper mountain sections

  • A practical overnight/stop option for itineraries linked to Ogizawa access

• When to Go

  • Best window: July–August for the most reliable access

  • Early season can include snow travel higher up the route; late season weather turns faster.

• Who Is This Hut For

  • Hikers heading to Harinoki Pass / Harinoki-dake who want to split the approach

  • Early starters aiming to manage heat/traffic

  • Parties wanting a safety buffer before committing higher up

Why This Hut Is Worth Visiting

O-osawa-koya is not about luxury—it’s about strategy. Its value is in being a historic relay point that makes big days more manageable and provides a controlled place to rest before the upper alpine terrain.