Location: Shimamaki, Shimamaki-gun
Elevation: 1337m (~1050m elevation gain)
Length: Half day+ (~12km roundtrip)
Hiked on: May 2nd, 2017
Mount Fumonnai is a sub-peak of Mount Kariba, the tallest peak south of Mount Yotei. While Kariba itself cannot be reached easily until mid to late May when the road accessing its eastern side opens, Fumonnai offers an alternative that is slightly easier to reach even during the middle of winter.
The exact length of the hike will vary depending on the snow conditions. until April you’ll be starting the hike right at sea level which increases the length of the hike to around 18km roundtrip, however once the snow begins melting at the bottom of the hike the hike becomes shorter and shorter.
At the time I did the hike you could go all the way to the gate on the logging road that goes off Route 229 (consult this Yamareco post for the exact spot). Unfortunately this also meant I had to walk up the logging road quite a bit to find a spot with enough snow for me to get onto the ridge that would take me higher up whereas you could just climb straight up when there is more snow coverage.
It’s hard to give exact directions for where you need to gain the ridge so you’ll have to change your plans according to the snow conditions. Ultimately you’ll want to get onto the broad ridge with a flat top around 600m in elevation.
Once on the ridge, keep following it up as it steepens and narrows. After the initial flat bit you’ll hit one steep bit, at the top of which you will see Fumonnaidake directly in front off you. It’s a long gradual climb from there that should be fairly obvious in clear weather but you’ll want to make sure you’re going the right direction if visibility isn’t great.
Eventually you’ll get to the high point where you’ll be hit with an amazing view of Kariba in front of you. The ridge continues slightly to the left leading to Kariba, and Fumonnai is just a short walk to your right.
From the peak you can drop the steep face to the north, however dropping anything more than 50m or so will mean having to climb back up. In winter, you can probably ridge the gully all the way down around to 300m where you should be able to join back onto your climbing track, but avalanche risk is high and you’ll need to be well aware of where you’re going. You can also ride down along the ridge which is mellow but fun with great views of Mt Yotei and the Niseko Range.
You can also continue onto Kariba by following the ridge running south, however it’s probably another 2~3 hour round trip so make sure you will have enough time and energy to get back.