Mt. Ontakesan

Mt. Ontakesan (おんたけさん, 3,067m) is an independent peak straddling Otaki Village / Kiso Town (Nagano) and Gero City (Gifu), selected in Kyuya Fukada’s One Hundred Mountains of Japan. A long-revered sacred mountain, it is the second-highest independent peak in Japan after Mt. Fuji. An active volcano remembered for the September 27, 2014 phreatic eruption (63 dead or missing — Japan’s worst post-war volcanic disaster).

In 2026 you can reach the summit (Kengamine) from either Kurosawaguchi or Otakiguchi. The Otakiguchi course (from Tanohara) was opened beyond Otaki Summit at 09:00 on 10 July, so it now continues all the way to Kengamine. Highlights include the mountain’s history as a religious site and 360° panoramas from the summit and Ninoike (Japan’s highest lake).

*Timetable last checked: 2026年09月05日

1. [Outbound / Return] Kiso-Fukushima Station ⇔ Tanohara (Ontake Kotsu Bus, weekends / holidays + 5 Aug weekdays only)

For the Otakiguchi trailhead Tanohara (2,180 m), take the Ontake Kotsu (Otaki Village-operated) bus from Kiso-Fukushima Station front approx. 1 hr 15 min・one-way ¥1,500・round-trip ¥2,500. 2026 operating period: July 4 – October 18, weekends / holidays only + August 3-7 and August 10 (weekdays), 2 services per day (morning 8:40 dep・afternoon 13:45 dep). Private car: Tanohara parking (~200 spaces, free, congested in summer). Tickets sold at Kiso-Fukushima Station front ticket office; pre-confirmation / reservation required (Otaki Village Office ☎0264-48-2001).

Operating period : 2026 July 4 (Sat) – October 18 (Sun), weekends / holidays + August 3-7 and August 10 (weekdays)
Travel time : Kiso-Fukushima Stn → Tanohara ~1 hr 15 min
Fare : One-way ¥1,500・round-trip ¥2,500
Frequency : 2 services per day (morning 8:40 / afternoon 13:45)

Kiso-Fukushima Stn → Tanohara (Ontake Kotsu Tanohara Line, 2026 operating period, hikers)

Tanohara → Kiso-Fukushima Stn (Ontake Kotsu, return, 2026 operating period)

Note : Operating period and timetable should always be pre-confirmed at the Otaki Village official PDF and Ontake Kotsu official site. Operation is limited to weekends / holidays + 5 August weekdays; on other weekdays private car is essential. After descent, Ontake Onsen “Otaki-no-Yu” (bath ¥600) or Kiso-Koma Kogen Shikanose Onsen is recommended.

Reference : Otaki Village — Tanohara Line bus official ｜ Ontake Kotsu — route buses
Contact : Otaki Village Office (bus inquiries) ☎0264-48-2001 / Kiso Town General Affairs Crisis Mgmt (volcano info) ☎0264-22-4280

2. Otakiguchi course, restriction-relaxation period, suggested plans

About Mt. Ontakesan
At 3,067 m on the border of Otaki Village / Kiso Town (Nagano) and Gero City (Gifu), as an independent peak it is second only to Mt. Fuji in height. Selected in Kyuya Fukada’s One Hundred Mountains of Japan, a long-revered sacred mountain. The September 27, 2014 phreatic eruption killed or left missing 63 people (Japan’s worst post-war volcanic disaster). The volcanic alert level was raised from 1 to 2 on January 16, 2025, then lowered from 2 to 1 on May 20, 2025, and is currently Level 1. Restrictions are relaxed from 08:00 on 1 July for Kurosawaguchi and from 09:00 on 10 July for Otakiguchi, both until noon on 14 October, and Kengamine can be reached from either. The summit and Ninoike Pond (Japan’s highest lake, 2,905 m) offer 360° views, with religious stone statues lining the route.

Trail overview (2 main courses, 2026 restrictions reflected)

• Otakiguchi course (from Tanohara, restriction-relaxation period only): Tanohara worship-site → 8th Station → Otaki Summit → Kengamine. Open from 09:00 on 10 July to noon on 14 October, about 3 hr 10 min up and 1 hr 50 min down. From Otaki Summit you can also cross to Kurosawa Crossing via the Ninoike traverse
• Kurosawaguchi course (using the Ontake Ropeway, Intermediate, ~6 hr): Ontake Ropeway Iimori-Kogen Station → 9th Station → Kengamine. Open from 08:00 on 1 July to noon on 14 October. Helmet rental at the base station
• Nigorigo-Onsen course (Gifu side, Expert, ~9 hr): Long route, for strong hikers

Ontake Ropeway (gateway to Kurosawaguchi, 2026): the base of the Kurosawaguchi route. It operates from April 25 to November 8 (planned), at ¥2,600 round trip / ¥1,400 one way for adults, running frequently; helmets can be rented at the base-station shop. However, public transport to the ropeway base station is limited, so access is mainly by private car or taxi — inquire in advance with the Otaki Village Office or Kiso Town.

Mountain huts / hot springs (2026 information)
– Otaki Chojo Sanso (2,940 m, ☎080-6924-6051): Open only during restriction-relaxation period, 1 night with 2 meals ¥10,000~・room-only ¥7,000~, reservation required
– Ninoike Hut (2,905 m): Open only during restriction-relaxation period, reservation required
– Ontake Onsen “Otaki-no-Yu” (Otaki Village, bath ¥600)・Shikanose Onsen (Kiso-Koma Kogen)
– Tanohara parking: ~200 spaces, free

Climbing season / flora: Early July to early October. July: koma-kusa, iwa-gikyo colonies (8th-9th station), religious stone statues. Late September to early October: autumn colors. Snow remains around the summit / Kengamine area until early July.

Cautions
– Volcanic alert level 1, prepare for sudden eruption: Always check JMA volcano info before departure
– Kengamine is only reachable during the relaxation period (Kurosawaguchi from 08:00 on 1 July, Otakiguchi from 09:00 on 10 July, both until noon on 14 October): everything is off-limits outside it, and the Okunoin and crater-rim circuit stay closed even during it
– Helmet strongly recommended: 2014 eruption lesson; pre-check shelter locations
– Water only at huts: No water sources on the trail; carry at least 2 L
– Bus only weekends / holidays + 5 Aug weekdays: Private car essential on other weekdays

Emergency contacts / inquiries

• Otaki Village Office (bus / climbing info): ☎0264-48-2001 / Kiso Town General Affairs Crisis Mgmt (volcano info): ☎0264-22-4280
• Kiso Police Station (climbing notification / mountain rescue): ☎0264-22-0110
• Otaki Chojo Sanso (during restriction-relaxation period): ☎080-6924-6051
• JMA Mt. Ontakesan volcano info: JMA Mt. Ontakesan

Suggested plans (adapted to the 2026 restrictions)

• ① Otakiguchi day hike by bus (to Kengamine): Kiso-Fukushima Stn 8:40 → bus → Tanohara 9:55. Hike Tanohara worship-site → 8th Station → Otaki Summit → Kengamine and back, then Tanohara 15:50 dep → Kiso-Fukushima Stn 17:05. The standard time is 3 hr 10 min up and 1 hr 50 min down — 5 hours in total — against the 5 hr 55 min the bus timetable allows, leaving barely 55 minutes for breaks. That is very tight, so if you walk at a relaxed pace, turn back at Otaki Summit (about 4 hours round trip) or stay at the Otaki Chōjō Sansō hut.
• ② For Kengamine, use Kurosawaguchi (via the Ontake Ropeway): Ride the Ontake Ropeway from the base station to Iimori-Kogen Station, then continue via the 9th Station to Kengamine. The ropeway does much of the climbing for you, so you are not tied to the bus timetable. Helmets can be rented at the base station.

Reference : Kiso Ontake Safety Info ｜ Otaki Village — Tanohara Line bus official

Photo by Alpsdake