This outcrop is where two tectonic plates collided to create the Hidaka Mountains. This extensive thrust fault continues for 140 km north to south and a small section of the derivative fault can be seen. The black area to the left is serpentinite rock and the greenish area on the bottom right underwent metamorphism to become metagabbro. The metagabbro is believed to be part of the oceanic plate that became caught in the subduction zone between the continental plate during the plate collision.

Visitors to this geosite should be careful to passing vehicles, as it is located on the shoulder of a national highway.