This large boulder was washed down from the mountains, during the Taisho Mudflow of May 24th, 1926.

It was originally located 30m to the south, on the side of the road, but it was later moved to its current location, during the refurbishment of the adjoining parking lot.

The boulder is estimated to be 3.7m tall, and weigh 68 tons.
It is understood to have been washed down in the mudflow, based on evidence from a photo held by the Kamifurano Town Folk Museum.

On top of the boulder is a memorial plaque, which was constructed exactly one year after the Taisho Mudflow.

The victims of the Taisho mudflow, and related organizations, used the boulder as a pedestal for the memorial, so that the memory of those who suffered in the disaster will not be forgotten.

While there are other memorials to the Mr. Tokachidake disaster, this is the only one to be built by public institutions and funded by donations.

Also, this is the only monument to the Tokachi Mudflow which uses a boulder as a pedestal.