Iwaki-san Daikoku-zawa Ski Touring


Posted on Jan 22, 2021
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Posted on Jan 22, 2021

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Reading time: 4 min


3.5 hours





Highest point



Snow Icon | Hokkaido Wilds

Best season

Daikokuzawa (大黒沢) is an iconic volcanic valley descending from Iwaki-san's (岩木山, 1625m) summit, popular among serious ski tourers seeking a long, rewarding day out on western Aomori's classic volcano. Situated in the Tohoku region in northern Honshu, the area receives apocolyptic amounts of snow during January and February, lingering well into the spring months. This route ascends Iwaki-zan's southeastern slopes from the top of the Hyaku-sawa Ski Area, and descends towards the east-northeast. You'll need someone to shuttle you back to your car at the ski area, but the hassle is worth it - this may be one of the longest descents in the area (1200m vertical loss).

We visited this route on Jan 28, 2020

Route Map

Need to know details


Iwaki-san is a large free-standing volcano located on the western side of Aomori Prefecture, Honshu’s northern-most prefecture. This route is concentrated on the southeastern quadrant of the conical volcano, starting at the top of the Hyaku-zawa Ski Area, here. Note that this route is a traverse – you’ll end up on the eastern side of the mountain, far from your start point.

General notes

There’s a few ways to experience the grandeur of Iwaki-zan’s Daikoku-sawa valley on the eastern side of the mountain. One is to climb up the valley, and then ski down. This is the logistically rational choice. However, if you can arrange transport from the end of the route, then starting from the top of Hyakuzawa Ski Area to the south will cut out around 700m of climbing. The traverse from the ski area requires some solid time in very exposed alpine conditions, so the views from the upper section are epic. At the same time, that exposure will require good snow-safety skills and experience. It’s perfectly possible to climb to the summit on this route – if planning to do so, add an extra two hours to the total time.

  • Shuttle options: Shuttle options are scarce during the deep winter months. Accommodation providers in the area, however, will generally be open to meeting you at a pre-arranged time at the end of the route, here, at the bottom of the orchards. A good option for accommodation is Pension Wonderland – the owner is an avid outdoors-person. He was very kind to shuttle us back to our car at the ski area after our traverse.
  • Summit push: Approaching the summit under most conditions will likely require crampons, and ice-axe for self-arrest in the event of a slip.


Route details

Take the lift to the upper lift station at Hyaku-zawa Ski Area – this will set you back a massive 250yen. From here, start skinning up the ever-narrowing broad shoulder directly above the lift station. You may be pushing through thick re-growth for the first 500m or so, but things soon start to thin out as you enter more mature-growth forest. At around 1050m altitude, you may find your ridge fading out, and you’ll need to cut across some tight gullies to gain a ridge directly to the climber’s right. It’s a little convoluted until the tree line. Beyond the tree line, skiers will be exposed to the elements as well as heightened avalanche risk. Take extreme care when crossing the snowfield at around 1350m – a slide here will send skiers over high bluffs 100m below.

From just below Ganki-san, rip skins and enjoy the descent. As always, check snow stability, particularly in the upper alpine bowl. Further down the slopes are well anchored – you’ll be doing classic Tohoku tree skiing among well-spaced beautiful birch trees. About half way down the valley, it may pay to stick to the skier’s right ridge-top, as undergrowth can get thick on the valley walls.

Eventually, you’ll join up with the summer trail. Enjoy the last 500m or so skiing through gorgeous apple orchards down to the upper-most snow-clearing end.

Route Timing
Up | 2hrs
Down | 1hrs

The route timing above is as we did it – skirting below the summit on the alpine traverse. If planning to head to the summit, you’ll need to factor in time to change to crampons etc – allow another two hours to be safe.


Public transport:

There’s very patchy public transport around Iwaki-zan. The closest bus stop to the end of the route is the Yayoi Bus Stop (弥生バス停, location). From here, there’s five buses per day towards Hirosaki City (timetable here). From Hirosaki, you’d then get another bus back to the Hyaku-zawa ski area, by catching a bus to Hyakuzawa Onsen (Hyakuzawa Onsen Mae Bus Stop, 百沢温泉前, location). From there it would be a 1.5km walk to the ski area. Don’t count on taxis being available – even if you could call a taxi, it would be coming from Hirosaki City, a solid 30 minute drive away.

By car: 

There is ample parking at the Hyakuzawa Ski Area car park, here. At the end of the route, if you do depot a car there in advance, make sure to park well off the side of the road, so as to not obstruct traffic. You may need to spend 20 minutes clearing a spot to park.

Physical maps
Official Topo Map: Iwakizan (岩木山) – map no. NK-54-24-9-3
Official Topo Map 2: Todurasawa (十面沢) – map no. NK-54-23-12-4

NOTE: The official 1/25000 topo map(s) above can be purchased for 350yen from Kinokuniya bookstore next to Sapporo Station or online (in Japanese).

Snow and route safety

This route involves an exposed alpine traverse across high-risk avalanche terrain. Take the appropriate precautions, including observations of snowpack, as well as checking the weather forecast in advance. Being a free-standing volcano, wind and weather conditions can vary dramatically depending on aspect. Make conservative decisions once above the tree line.

Weather forecast

Windy.com weather forecast for Iwaki-san Daikoku-sawa
Onsen nearby

The small village of Dake Onsen (嶽温泉) on the southern side of Iwaki-zan has a number of very traditional onsen options. Do note, however, that many close to day visitors relatively early in the day. We visited Dake Hotel Onsen (嶽ホテルlocation, 550yen), and loved the traditional onsen vibes.

Extra Resources

See a detailed overview of this route (in Japanese) on p. 34-35 in the excellent RSSA Backcountry Skiing 100 Mountains 山スキー百山 guidebook by the Research Society of Ski Alpinism スキーアルピニズム研究会 (available on Amazon.co.jp).

Guide Options

If you’d like to ski this route and/or explore other areas of Tohoku together with a local certified guide, get in touch with Kenichi. He’s JMGA certified, and spends a large chunk of his year guiding clients on mountaineering trips around the world. He’s Honshu based though, and guides clients from around the world to prime locations on the island, including Tohoku.

Show Full Route Notes Close Route Notes

Route Trip Notes

After the morning’s “we bought the packraft all this way so we’d better use it” trip down the Iwaki river, we drove back to the eponymous mountain under a darkening sky of Altostratus; the warm weather we knew was coming had finally decided to show up… certainly not a sight of delight for the four of us.

The starting off point for today’s tour was the  Iwaki Hyakuzawa ski resort (岩木山百沢スキー場) which is on the south eastern slopes of Iwaki-zan. It’s basically on the exact opposite side from our previous day’s tour at Aomori Spring. Hyakuzawa has three fixed grip chairlifts, nothing fancy to be sure, but with a few solid days touring under our belt already, the 400m of free (well ¥250) lift serviced vertical was much appreciated to get us started on up the hill. We’d driven ourselves there in my Honda adventure van and had arranged a pickup by our very gracious host at Pension Wonderland as the descent runs down a completely different drainage. 

Rob’s heel piece was once again refusing to turn into walk mode and given that we were now ‘in civilization’ we were able to sort things properly. The combination of my extensive knowledge of appropriate lubrication and Rob’s ability to translate “just needs some CRC mate” into Japanese meant things were soon sorted for the rest of the trip. 


The overview photo from the Hyakuzawa website provides a pretty good view of the first section of the uptrack. It also gives a view of the potential/peril to lookers right. Some very tempting terrain that has large slopes above it and high consequence terrain traps in the bottom. Contemplate with great caution and and be aware that you’ll be skinning out as well.

We climbed the ridge immediately above the lift. The ‘cut block’ of vegetation is obvious and then we stuck in the trees as we climbed further.  The now gathering cloud base meant that visibility was coming in and out but we were still able to make out the obvious gentler slopes to lookers right. We traversed these and stopped for a snack break and a few photos.



Hyakuzawa overview from https://www.hyakuzawa-ski.com/course.html
Iwaki-san Daikoku-sawa Ski Touring Route (Aomori, Japan)
Iwaki-san Daikoku-sawa Ski Touring Route (Aomori, Japan)

With cloud still coming in and out we continued to contour around to the north so as to be certain of dropping into the correct drainage.  Depending on snow and wind conditions it’s likely that there’s reasonable skiing straight down the obvious ridge as well. Visibility notwithstanding, the first pitch produced some great turns for all of us through a wide open and well supported bowl. We then tracked around the ridge and into some of the now familiar old growth starkly deciduous Tohoku birch forest. Snow conditions were holding up, but, it was a bit of a stop-start process to ski down the ridge in order to maximize quality turns on each pitch of skiing. With a bit more exploration there’s probably a good session of tree-laps to be had even just in this section.

Iwaki-san Daikoku-sawa Ski Touring Route (Aomori, Japan)
Iwaki-san Daikoku-sawa Ski Touring Route (Aomori, Japan)

As we descended further the year’s lighter than normal snowfall began to come into play and we found ourselves bashing through the undergrowth and then eventually moving into walk mode to hike out along the gully floor. While we didn’t make the summit on this trip this does look to be a reasonable route to take as an approach. We’ll be back again for sure.

The last turns of the day were gentle bum-wiggles through open apple fields; the Japanese approach their [boutique] horticulture with the same pride and perfection that they apply to most pursuits and even now, late into the afternoon on a mid-winters day, local farmers were out pruning and pampering their trees. It was close to dark once our ride arrived and we all headed back to Pension Wonderland for dinner with our host family.

Iwaki-san Daikoku-sawa Ski Touring Route (Aomori, Japan)
Iwaki-san Daikoku-sawa Ski Touring Route (Aomori, Japan)

Comments | Queries | Reports

Done this route to Iwaki-san Daikoku-sawa, or others nearby? Thinking of doing it? Please post any feedback, reports, or queries here. Thanks!

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