Mt. Okusangai

Mt. Okusangai (奥三界岳, 1,811 m), straddling Nakatsugawa (Gifu) and Kiso District (Minamikiso and Ōkuwa) in Nagano, is a peak of the Atera Mountains and one of the 300 Famous Japanese Mountains and the 100 Mountains of Gifu.
A single trail running up from Yumori Park on its southern foot is the only route, passing a string of high-volume falls and streams along the Kawakami River — the Ryujin Falls and the 17 m Doketsu Falls. The summit is wrapped in conifers and kuma-bamboo grass, with an observation deck looking out to the Central Alps and Mt. Ontake. It is a long route of about 15.8 km round trip and over 8.5 hours, including a long forest-road walk — a day hike for the fit. By public transport you reach the Yumori Park entrance by bus from Sakashita Station on the JR Chuo Main Line.

The start is the Yumori Park entrance (drivers use the car park at the Kawakami forest-road gate beyond it, about 10 spaces). You walk the Kawakami forest road about 9 km past the Ryujin and Doketsu falls to the trailhead at the end of the Maruno forest road, where a forestry-office hut stands; from there a steep climb and stream crossings lead to the summit. From the Kawakami forest-road gate to the summit, the round-trip time is about 8 hours 40 minutes (about 5.5 hours up, about 3 hours down), about 15.8 km, with about 1,288 m of gain. There is no staffed hut on the trail, so it is a day hike; but as the route is long, consider a night at the Yumori campsite or similar.
The stream crossings can become impassable when the water is high, such as the day after heavy rain; there are also collapsed scree, root steps, marshy ground and brush. The season is late May to early November, from fresh green to autumn colour; winter is not usual owing to snow.

*Information last checked: June 14, 2026

Access to the trailhead (Yumori Park)

1. [Outbound] Sakashita Station → Yumori Park entrance
2. [Return] Yumori Park entrance → Sakashita Station

1. [Outbound] Sakashita Station → Yumori Park entrance

From in front of JR Chuo Main Line Sakashita Station, take the Kitaena Kotsu “Yumori Park Line” bus (via Katarai-no-sato, bound for Yumori Park) to its terminus, the Yumori Park entrance (about 15 minutes, fare around ¥500). From the Yumori Park entrance you walk further up the forest road to the Kawakami forest-road gate. The table below is the holiday schedule (revised October 1, 2025), with only 3 services a day. As the route is long, the first bus (Sakashita Station 7:25) is essential; weekdays run on a different schedule, so confirm the latest officially.

Bus timetable ①: Sakashita Station → Yumori Park entrance (Kitaena Kotsu Yumori Park Line, holidays)

Reference: [Kitaena Kotsu timetable (Yumori Park Line)]

2. [Return] Yumori Park entrance → Sakashita Station

After descending, take the Kitaena Kotsu “Yumori Park Line” (bound for Sakashita Station) from the Yumori Park entrance back to Sakashita Station. As Mt. Okusangai is a long route of over 8.5 hours round trip, keep ample margin for the last bus (Yumori Park entrance 16:55). In case you cannot make the last bus, match your pace to the timetable in advance.

Bus timetable ②: Yumori Park entrance → Sakashita Station (Kitaena Kotsu Yumori Park Line, holidays)

Reference: [Kitaena Kotsu timetable (Yumori Park Line)]

Route and safety notes

Route: Yumori Park entrance → Kawakami forest-road gate → Ryujin Falls → Doketsu Falls (17 m) → end of the Maruno forest road (forestry-office hut, trailhead) → steep climb and stream crossings → Mt. Okusangai (summit observation deck). Combining about 9 km of forest road and about 7 km of trail from the gate, it is about 15.8 km round trip and about 8 hours 40 minutes. It is a day hike, but if the first and last bus times leave little margin, a night at the Yumori campsite or similar is safer.

Stream crossings: the trail has bridgeless stream crossings that can become impassable when the water is high, such as the day after heavy rain. Do not force it after rain; turn back if the water is high.

Hazards: there are collapsed scree, root steps, marshy ground and brushy sections, so watch your footing and the route. The long forest-road walk is tiring, so manage your pace and stay hydrated.

The summit: an observation deck stands amid the kuma-bamboo grass, looking out to the Central Alps and Mt. Ontake. Much of the route is hemmed in by forest with poor visibility, so check your position with a map and GPS.

Season and gear: the season is late May to early November. Even as a day hike the time on the move is long, so carry a headlamp, rain gear, warm clothing and plenty of food and water. Be prepared for leeches and bears (a bear bell).

In an emergency: call 110 (police) or 119 (fire/rescue). Always file a climbing plan.

Photo by Alpsdake / Wikimedia Commons, CC BY-SA 4.0