Road from Matsumoto to Takayama open March?

Just wondering if the beautiful mountain road from Matsumoto to Takayama would be open at the end of March? And if so, would we need snow tyres?
Many thanks.

Just wondering if the beautiful mountain road from Matsumoto to Takayama would be open at the end of March?

Yes, it is open around the year.

And if so, would we need snow tyres?

I recommend so. I encountered some snow on the road around Hirayu even in early April.

Thanks so much for your reply.
Would it be a pretty drive at that time of year?
Is the mountain region, just trying to think of the name starts with K, accessible? Perhaps worth a nights stop? (And a little hike).
Thanks

Would it be a pretty drive at that time of year?

The snow is mostly gone, but the greenery has not arrived yet (in the higher areas). Also, it is not the easiest road to drive. The driver will have to be very concentrated and won't be able to enjoy the scenery too much. But the surrounding mountains are quite nice, indeed.

Is the mountain region, just trying to think of the name starts with K, accessible?

Kamikochi opens on April 17, 2018:
https://www.japan-guide.com/e/e6040.html

Perhaps worth a nights stop? (And a little hike).

It usually still feels a little wintery at that time, but I think it could be very nice.

What about at the other end of the season - early December - would it require snow tires?