These mountains form a major part of the Yatsugatake-Chūshin Kōgen Quasi-National Park.

[2] These mountains consist of older eroded complex volcanoes, which were made by repeated volcanic eruptions over many thousands years.

The last eruption was estimated from 600 to 800 years ago at Mount Yoko of North Yatsugatake Mountains.

On one part of Mount Nishi under 1700m grows a rare form of spruce, Picea koyamae.

Humans have enabled the expansion of the red fox by leaving trash behind in the mountains.