Mt. Amakazari Hiking Guide: The Otari Onsen Route, Official Grading and the 2026 Autumn Rules

This guide is based on information from Nagano Prefecture, the Otari Village Tourism Association, Amakazari Kogen Campground and the Itoigawa Tourism Association, checked October 24, 2026. Conditions change, so check these pages before you go.

Mt. Amakazari (1,963 m) rises on the border between Otari Village in Nagano and Itoigawa City in Niigata, inside Myoko-Togakushi Renzan National Park. It is one of Japan's 100 Famous Mountains, known for its twin-peaked summit, the open slopes of Sasadaira below the top, the Arasugasawa gully, and beech forest that turns gold and red in autumn.

Autumn 2026: rules on the Otari side

The Otari Village Tourism Association announced the following on October 8, 2026:

Do not start climbing after 9:00 a.m. The association says later starts raise the risk of accidents.
On Saturdays, Sundays and holidays from October 10 to November 3, 2026, staff direct traffic at the trailhead, and a mountain consultation post staffed by the local rescue council (Otari team) is open at the Otari Onsen trailhead.
Hikers park only at the trailhead car park and the second car park. Parking on the forest road (Rindo Himekawa-Myoko Line) is banned.
When both are full, parking moves to near the Amakazari Kogen bus stop. From Amakazari-so to the trailhead is about 60 minutes on foot.
The road to Lake Kamaike stays open.

Source: Otari Village Tourism Association notice (Japanese)

Official grading

In Nagano Prefecture's mountain grading (2026 list), Mt. Amakazari via Otari Onsen is rated stamina 3, technical C: a round trip from Amakazari Kogen Campground (1,150 m) of 7.0 hours excluding breaks, 8.0 km, with about 1,040 m of ascent and descent. Technical C is a step above the B rating given to many popular peaks, so expect steep sections and rocky ground near the top.

Source: Nagano Prefecture mountain grading (Japanese) (2026 list, PDF)

Hikers resting on the rocks of Arasugasawa with autumn colours around them — Arasugasawa. Photo: Koda6029, Wikimedia Commons (CC BY-SA 4.0)

Routes

Otari Onsen route (Nagano side): the standard choice

Amakazari Kogen Campground → Arasugasawa → Sasadaira → summit → back the same way

This is the usual route for a first visit. The forest walk leads to Arasugasawa, where the view opens; after crossing the gully, a long steep climb brings you up to Sasadaira, and the last part to the summit is rocky. Early in summer, snow can remain in the gully.

Amakazari Onsen routes (Niigata side)

The Itoigawa Tourism Association lists two routes from Amakazari Sanso, a mountain inn at Amakazari Onsen:

Route	Up	Down	Parking
Omagari route	about 4 h 20 min	about 3 h 50 min	car park behind Amakazari Sanso, 15 cars
Nakanoike route	about 4 h 30 min	about 3 h 30 min	Amakazari Sanso car park, 10 cars

By car it is about 60 minutes from Itoigawa IC via Route 148 and Prefectural Road 483; by public transport, about 70 minutes by bus from Itoigawa Station. The association says the traverse to Mt. Nokogiri, Mt. Kigamen and Mt. Koma also starts from the Omagari trailhead; it is a separate, more serious undertaking.

Source: Itoigawa Tourism Association: Mt. Amakazari (Japanese)

The summit sign of Mt. Amakazari with mountains behind — The summit of Mt. Amakazari. Photo: ys-energy, Wikimedia Commons (public domain)

Getting to the Otari Onsen trailhead

By car

Amakazari Kogen Campground gives these driving times:

From Azumino IC (Nagano Expressway) via Route 147 (Omachi) and Route 148 (Hakuba): about 90 minutes
From Itoigawa IC (Hokuriku Expressway) via Route 148: about 50 minutes
From Nagano IC (Joshinetsu Expressway) via Route 19 and the Olympic Road through Hakuba: about 80 minutes

Turn north off Route 148 at the "Otari Onsen-guchi" junction, just after a tunnel; the campground is about 20 minutes from there.

By train and bus

Take the JR Oito Line to Minami-Otari, then the Otari village bus bound for Amakazari Kogen to the last stop. From there it is about 3 km (about 1 hour) on foot to the campground.

Source: Amakazari Kogen Campground access (Japanese)

Trailhead facilities

According to Amakazari Kogen Campground:

Free parking, about 100 cars in the first and second car parks
Flush toilets, a vending machine for portable toilets, drink vending machines and a free rest hut
The water in the rest hut is not drinkable as it is, but can be drunk after boiling
A hikers' free tent site (room for about 30 mountain tents, no reservations): 1,320 yen, 1,540 yen or 1,760 yen per person per night depending on the calendar
In 2026 the campground opened on May 30

Sources: For hikers (Japanese), 2026 season opening (Japanese)

Things to keep in mind

Start early. The route takes 7 hours without breaks, and in autumn the Otari side asks hikers not to start after 9 a.m. Daylight is short in late autumn.
Pace yourself before Arasugasawa. The hardest climbing comes after the gully, up to Sasadaira.
Snow in early summer. Snow can stay in the gullies; if you are not used to walking on snow, wait until it has melted.
There are no toilets on the mountain. Carry a portable toilet; one can be bought at the trailhead.
Long drive home. From the Tokyo area it is a long day of driving and walking; staying nearby the night before or after makes it safer.