Wanted to write about this one for a while, but missed the timing to capture fresh impressions. After starting to hike more and more I’ve discovered that I am affected by altitude sickness. Did not think too much of it until recently since there are plenty of hikes around Nagano in sub 2.7km elevation range. But lately we’ve found ourselves in situation where most of nearby mountains are explored apart from a few that we did not conquer previously due to altitude.

This time we picked Io (硫黄岳) in Yatsugatake mountain range as our final goal. Yatsugatake is a fairly popular tourist spot on eastern boarded of Nagano prefectures with neighboring Yamanashi. Having tried Yatsugatake last year, namely mount Aka, tallest of the range, I knew that going up there would likely give me a headache, as it did last time.

However to make myself a little less miserable we’ve booked a mountain hut (黒百合) to spend a night there at around 2.5km to hopefully adjust before summiting next day. Approach was fairly short, just 2-3 hours of hiking and a parking lot was conveniently located so we only had to do about 600m of elevation before checking in. Parking lot is actually handled by the onsen (奥蓼科温泉郷), so you are required to come say hi and pay the parking fee. We got there a little late, so had to rush for check-in which closes at 4pm but luckily we made it in time. Since we had a little time left before dinner at 5:30, we decided to look around. The hut is located nearby main ridge, so you can follow it either south to Io, our final destination, or north to check Nakayama (literally inner/middle mountain - probably the laziest mountain name one could think of on this range).

We found a few nice viewing spots and met a local, probably finishing traverse south, but the sun was setting on the opposite side so no pretty sunset pictures. Continuing further south on the trail we found out it went below the tree line and continued to descend so we decided to call it a day, went for dinner and tried to tuck in for sleep.

Huts usually serve breakfast quite early, this one had it scheduled for 5:30, apparently in Japan every ‘serious’ hiker wakes up early to finish their business in the mountains in the afternoon (which is also easy to tell since huts stop serving food around 2pm). I’m not very much on board with this mentality but there is no way but to comply.

Overall I felt pretty good on that altitude, had slightly elevated heart rate and only mild head discomfort. I did not get a lot of sleep though, maybe a few hours. But upon waking up I discovered that I’m feeling rested so after breakfast with another ハンバーグ (beef cutlet) and plenty of rice (of course!), we headed towards Tengu (天狗岳), our first summit on the list.

In between Tengu and Io we found another hut and a place that would serve very well to test various objects aerodynamic properties, we decided to skip the hut and get hot drinks on our way back. After passing through another forest section we started to get some good views on Io, our final target.

Like many mountains here it is a stratovolcano, but without its iconic conic shape as Fuji or even Myoko. Instead you can see its sulfurous cliffs and proud profile. From the summit you can see rest of range mountains, including highest of them all - Aka (赤岳). I’ll take revenge on that one later. Many people cotinued their traverse as there are multiple huts in between peaks which makes it a very convenient destination for multi-day hikes.

Being a highest point of our hike at just below 2.8km we started our way back, but picked a different trail to check out another hut nearby (オーレン小屋).

We started hiking quite early so it was around 11 when we reached the hut to find out that they’re about to serve lunch - perfect timing. Borsch was on the menu but I was fairly skeptical, since sometimes here they mix lemon in it making it sour. I was relieved to confirm with staff that it’s not the case this time.

On our way back we passed that hut in a saddle point, this time with some mist sweeping over the range for more spectacle.

From there backtracking was somewhat tedious, as it was mostly descent, we’ve arrived back to the hut we booked for night at around 3pm, so of course there was no more food served. Protein bars it is then.

Weirdly on the way back during descent I started to experience the same symptoms I had when ascending too high too quickly - mainly headache. I guess there is some equalization point when your body adjusts to pressure and oxygen level difference and when environment changes again it needs more time… not sure. Anyway we were pretty close to the car at this point so it did not bother me that much.

Back to the trailhead and one hour drive home. Yatsugatake mountain range is very special if you live in east Nagano as you can see them every day from pretty much anywhere and being able to just hop in the car for an epic traverse is definitely an awesome feeling.