You’ve got options in terms of how and where you start this route. I’ve included directions from the township of Kombu becasue theat’s your best public transport option. This route is one of a series that I am hoping to do around Rankoshi-chō (蘭越町) and I’ve got a blog-post here that provides an overview of all of them and some guidance for multi-day trips.
Starting from the Kombu township, you’ll ride north acros the Shiribetsu River (尻別川) and shortly thereafter begin climbing into the Hinode (日出) hills . There’s a little gravel track that will take you up to route 207 (or you can ride up the sealed road) and then you’ll drop down a bit to the East beofe climbing steeply up to the Yunosato Onsen subdivision.
The subdivision was established in the early 1970s, complete with tennis courts, hiking trails, an outdoor onsen among other amenities. This was at a time when Japan could see endless economic expansion in it’s future… Sapporo-salary-man needed a place to get away to for summer weekends in his Toyota Crown and Yunosato was where it was going to be at!…then salary-man forgot to have babies, and that being a bit of a requirement to keep growing the population and building lots of houses… Yunosato never really took off… So, on the map, Yunosato looks like an expansive and well manicured subdivision but when you get there you’ll find that it’s largely returned to nature. It’s an amazing place to explore, especially once you’ve riden up and across route 207 once again; you’ll find dual carriage way sealed roads running into mown grass roads into overgrown thickets that are all but impenetrable.
Yunosato is also a fantastic place to come for a snow-shoe in the winter as many of the roads aren’t cleared.
From Yunosato you’ll travel along some quiet sealed roads for a kilometer or so and then began a descent through deeper forested area to the Hot Spring Motomiyayakushi Shrine 温泉本宮薬師神社. This area was, until quite recently (mid 00’s at least), an onsen and the foundations and pool area are still visible on the ride. The buildings that are shown in Google’s satellite photos are no more, but unlike many older buildings in the area they have been fully removed rather than just being left to rot.
The road turns to gravel from here and about 250m up the road is the shrine (jinja 神社) itself. You’ll pass through the torii (鳥居) and then climb a grassy trail about 200m in length. As this climbs, the shinden (神殿) will come in two view. The whole shrine is very well maintained and as you continue past the ceremonial buildings you will find a small house like structure and more pipework for the onsen.
From the onsen area the gravel road begins to climb consistently once again through a series of sharp bends and then, as the forest clears to farmland, several large arcing corners. The various peaks of the Niseko range will be visible, as will Yōtei-zan (羊蹄山) in places.
You’ll continue on, crossing the Baba River (馬 場 川) which is a spring fed stream with a source up the road in Chisenpuri. The road is in fantastic condition all the way from Motomiyayakushi up to Route 66; a likely combination of both the hard work of the Rankoshi Town (蘭越町) administration and the near absence of vehicular traffic.
As you near Route 66 you’ll ride past a sealed road that climbs up from your left; you’ll be coming up this road on your return journey in an hour or so so make a mental snapshot.
Once you reach Route 66 turn left and travel about 300m up a short rise on the sealed road to find your downhill track on the left. You should be able to follow your nose on the descent as you once again cross farmland and then drop more steeply back towards the valley bottom. The trail was pretty obvious and pretty clear when I rode this in early June, but, I suspect that it’ll get quite jungle-ey come late summer. This section has potential to run pretty fast if you want but there are not big drops or any objective danger apart from the consequences of an off at speed.
You’ll emerge back to ‘civilization’ at a stream crossing and just down the road from a small farmlet. Turn left and ride a short distance on the sealed road before beginning the climb back up the ridge. The uphill stretch is much more clear of vegetation and so your progress will be restricted only by your fitness here.
You’ll end up back at the point you passed earlier in the ride. Turn right and double-back on your previous track for a couple of hundred meters before climbing new track once again back up to Route 66.
That’s about it; from here you can ride back down to Kombu or I’d suggest heading down Route 66 towards Kutchan for lunch, dinner or an onsen.