Ōnuma Quasi-National Park (大沼国定公園, Ōnuma Kokutei Kōen) is a 90.83 km2 (35.07 sq mi)[1] quasi-national park on the Oshima Peninsula in southwest Hokkaidō, Japan.

The park encompasses the volcanic Hokkaidō Komagatake (北海道駒ケ岳, Hokkaidō Koma-ga-take) as well as the Ōnuma (大沼) and Konuma (小沼) ponds, which abut against the west slope of the mountain.

Ōnuma and Konuma were created when mudflows due to eruptions of Hokkaidō Koma-ga-take dammed up depressions at the base of the mountain.

The ponds, which are dotted with watershields, are surrounded by birch and maple forests.

You can help Wikipedia by expanding it.This article about a national/quasi-national park or protected area in Japan, or related topic is a stub.