Information about Mount Asama (浅間山)

 In Hyakumeizan (百名山), Mountain information

Following last hiking week-end, you will find in this article all the practical information (mountain lodge, access…) for hiking around Mount Asama.

General information

Mount Asama is a stratovolcano which is part of the Asama mountain range and rises et 2568m (8,425ft) high. It is one of the most active volcano in Japan ; its last eruption dating from 2009. In reality it is made of three volcanos. The first one is Kurofu-yama (黒斑山) which is said to have erupted about 230,000 years ago. The second one is Maekake-yama (前掛山) which is supposed to have start erupted 15,000 years ago and the actual volcano.

This volcano is part of the Hyakumeizan (百名山), Japan’s one hundred famous mountains, and the Joshinetsu Kōgen national park (上信越高原国立公園). The restricted area changes depending on the volcano’s activity. If you decide to hike near the volcano, it is mandatory to check in advance the information on the restricted area and the volcano’s activity (see the security section below).

Because there is no mountain lodge nearby the summit due to the volcanic activity, the summit is made as day hike. However if you come by public transportation, because of the late start, you will have to spend a night either in Asama lodge or Takamine-kōgen plateau, making a two days outing for a one day hike.

For more information, check the below links:

Outings examples


Due to the volcano’s activity there is no proper mountain lodge nearby. In addition to this, emergency lodges are made to be used only in sudden volcanic activity while hiking, not to spend the night. Anyway it is forbidden by prefectural law to spend the night in the 4km area around the crater.

Kazankan emergency lodge (火山館)
Location: Located between Kurofu-yama (黒斑山) and Maekake-yama (前掛山).
Opened period: Opened all year. Being just 2km away from the crater, it is closed depending on the volcano’s activity. It belongs to the city of Komoro (小諸市).
Tel/Fax: 0267-22-1700
fax: 0267-23-8766
Web Site:
Comments: contrary to its “mountain lodge” look, it’s not made as a place for hikers to spend the night. You cannot plan to stay there for the night. Consider it just as a rest house where you can refill water and take a break in the middle of your hike.
Yarigasaya emergency shelter (槍ヶ鞘避難小屋)
Location: It is located nearYarigasaya summit, just south of Maekake-yama summit.
Opened period:
Web Site:
Comments: It is a very simple emergency shelter in case the volcano suddenly erupt. It is not made for spending a night in it.
Asama emergency shelter (浅間山避難壕)
Location: These are 2 very simple sheet-metal shelters located between the crater and Maekake-yama summit.
Opened period:
Web Site:
Comments: Don’t plan to spend the night in there! They are just made to shelter in case an eruption starts when you are nearby.


To find a place to stay you have to go out of the perimeter of 4km from the crater.

Asama lodge (浅間山荘)
Location: It is located South-West of the volcno, at the start of the trail.
Opened period: Opened all year. Reservation mandatory.
Tel/Fax: 0267-22-0959
fax: 0267-25-2255
Web Site:
Comments: More than a simple lodge, it is a complex with hot sping (Tengu-spa), camping area, rental lodges…
Takamine-kōgen plateau (高峰高原)
Location: Takamine-kōgen is a plateau, Located 4 km as the crows flies west of the volcano. Accessible by the road pass of Kurumazaka-tōge (車坂峠) there is a ski resorts and some hotels are opened all year.
Opened period: all year
Tel/Fax: 0267-22-1234
fax: 0267-25-3380
Web Site:
Comments: Contact the town of Komoro‘s tourist office for more information.
Yu-no-maru-kōgen (湯ノ丸高原)
Location: Yu-no-maru-kōgen is a hot-spring and ski resort further West of Takamine-kōgen. The resort is a good start/end if you want to do a two days hike with a stay at Takamine-kōgen. There are several accommodations opened both winter and summer.
Opened period: all year
Tel/Fax: 0268-62-1111
fax : 0268-67-3337
Web Site:
Comments: Contact the town of Tōmi (東御市)’s tourist office for more information.

Access from Tōkyō

To check for train schedules, use the following site (in English) :

Take a shinkansen from Tōkyō (東京) up to Sakudaira (佐久平). It takes about 1:30 and cost 5660¥s¥ without reservation and 6370¥ with reservation.

To/From Asama-sansō (浅間山荘登山口)
Take a JR bus from Sakudaira train station towards Takamine-kōgen (高峰高原) and get off at Asama-tozan-guchi (浅間登山口) bus stop. Depending on the days there are 2 to 4 bus a day. It takes about 45 minutes and costs 860¥. Check this page for bus timetables (in Japanese). You will then have to walk for about 50 minutes on the road to reach the start of the trail from Asama-sansō (浅間山荘). Going back to Asama follows the exact same way reverse. Depending on days the last bus (2011 timetables) stops at Asama-tozan-guchi bus stop at 16:11 or 17:21 on its way to the station.

It is possible to do the hike from Asama lodge to Maekake-yama as a day hike if you take the first train from Tōkyō (Asama #501, leaves at 6:24) and take a taxi to go to the lodge from Sakudaira train station and also on the way back. It costs about 7000¥ per trip.

To/From Kurumazaka-tōge pass (車坂峠)
The same bus goes up to the pass. You just have to go down at Takamine-kōgen-hotel-mae (高峰高原ホテル前) bus stup. It takes about one hour from Sakudaira station and costs 1020¥. To go back home from the pass follow the same way but reverse. Depending on days the last bus (2011 timetables) stops at Takamine-kōgen-hotel-mae bus stop at 15:52 or 17:02 on its way to the station. A hot spring is located 30 minutes walk West of the pass, at the last stop/start of the bus back to the station and makes it a good hike end.

To/From Yu-no-maru-kōgen (湯ノ丸高原)
If you are looking for a 2 days outing, you can hike from Asama-sansō to Yu-no-maru-kōgen (or the other way around) and spending the night at Kurumazaka-tōge on the way. From Sakudaira station again, take a bus from Chikuma bus company (千曲バス) up to the terminus at Yu-no-maru (湯ノ丸). It takes about one hour (the price is not communicated). The problem is that there are only two bus a day which leaves the station at 9:40 and 14:35 and leaves Yu-no-maru for the return trip at 11:00 et 16:00 (2011 timetables). The last bus being at 16:00 it is a bit early especially if you want to bath in an onsen before going back home. Check bus timetables by clicking on the (電子ブックを開く) link from this page and go to page 26 (for 2011 document).


Minimum necessary maps to hike around Mount Asama are:
1/25000地形図、浅間山、長野6号-4、 NJ-54-36-6-4 (Asamayama, Nagano 6-4, NJ-54-36-6-4)
1/25000地形図、嬬恋田代、長野10号-1、 NJ-54-36-10-1 (Tsumagoitashiro, Nagano 10-1, NJ-54-36-10-1)
1/25000地形図、車坂峠、長野10号-2、 NJ-54-36-10-2 (Kurumazakatoge, Nagano 10-2, NJ-54-36-10-2)



As mentionned previously, Mount Asama is one of the most active Japanese volcano with its last eruptions dating from 2004, 2008 and 2009. Depending on its activity, the restricted area changes. As of today (August 2011), the activited is rated as 1 and it is possible to hike up to the summit of Maekakeyama, but the main crater area is forbidden. Level 1 is the lowest level on a scale of 5.The forbidden area can be enlarge at any time. Respect it, its put in place four safety. It means that the off limit area is limited to 500m around the crater where gaz are emitted. However it doesn’t mean that the volcano is safe and will not sudenly wake-up. If you decide to hike up to Maekakeyama, you do it at your own risks. As such if you want to hike near Mount Asama it is mandatory to gather in advance as much information as you can on its activity level.

If the grounds shakes, the volcano starts to make noise, emit smoke or starts to erupt or if you feel any danger while you are hiking it is recommended to either hide yourself in one of the shelter (I recommend Kazankan as the others don’t seem to be much of a protection) or walk down to Komoro city. Sirens and speakers are placed at shelters and at the summit of Kurofuyama to warn hikers of danger. If you hear them, take shelter or evacuate.

Finally be careful with gas when strong wind blows from North-East, East or South-East.

Information on volcano’s activity (in Japanese) :

In winter, all members of your party should be equipped with a beacon, a shovel and a probe and trained on how to use them. These devices do not prevent avalanches! They are used to rescue your partners caught in an avalanche. So even if you are equipped and trained, it is your responsibility, to evaluate on the field the ever changing snow conditions, the avalanche danger, which is the safest route and if it is wiser or not to go back and cancel your outing.

Check the weather forecast on the english page of the Japan Meteorological Agency :

Mountain conditions information (in addition to the above sites):

Other useful numbers in case of emergency

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