Hi, is this route likely to still be open at this time of year?
Thanks!

I did it just one week ago, so yes. But avoid cold days and thus the risk of ice. The surfaces are rough and there's nothing to drink. It's pretty much deserted, so if you fall and break your arm it will be hours till anyone notices you. But it's a memorable ride.

Mega, thank you very much!

FYI the road was closed yesterday, at the tunnel where you turn left and cross Fukashiro Lake and pass Koganezawa Park.
The sign said it was due to “a collapse” as far as my limited Japanese could tell me 😄

Oh dear, I assumed that you knew about rindō. Like most rindō, there's always a barrier at each end. Nine days ago, both were in place. We went around them. By contrast, the rindō over Iriyama tōge really is blocked, and that down to the north (Ōme) from Ōdawa really is too, because of forestry work and a landslide respectively.

Oh, I see! I’ve only recently moved here and this was my first ride since getting my rinko bag.
A big truck came through the gates just as I was trying to decide whether I should go around them or not, and I chickened out!
Still managed a good loop by heading up to Okutama Lake and coming back over Okutama Shuyu Road.
I think I’ll join a group ride next time!