is a river in

Hokkaidō is Japan, Japan's Japanese archipelago, second largest island and comprises the largest and northernmost Prefectures of Japan, prefecture, making up its own List of regions of Japan, region. The Tsugaru Strait separates Hokkaidō from Honshu; th ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the n ...

. The Rumoi is in length. It traces its source to

Mount Poroshiri or sometimes Mount Horoshiri is located in the Hidaka Mountains, Hokkaidō, Japan. Its name was derived from a phonetic kanji transcription of the Ainu words for "great mountain", ''poro-shiri''. It is the highest mountain in the Hidaka range, a ...

in the Hidaka Mountain range, and flows across Rumoi Subprefecture in the west of

and empties into the

Sea of Japan The Sea of Japan is the marginal sea between the Japanese archipelago, Sakhalin, the Korean Peninsula, and the mainland of the Russian Far East. The Japanese archipelago separates the sea from the Pacific Ocean. Like the Mediterranean Sea, i ...

. The

mouth In animal anatomy, the mouth, also known as the oral cavity, or in Latin cavum oris, is the opening through which many animals take in food and issue vocal sounds. It is also the cavity lying at the upper end of the alimentary canal, bounded on ...

of the Rumoi River is in the city of

Rumoi is a city located in Rumoi Subprefecture, Hokkaido, Japan. It is the capital of Rumoi Subprefecture. As of September 2016, the city has an estimated population of 22,242 and the density of 75 persons per km2. The total area is 297.44 ...

References

Rivers of Hokkaido Rivers of Japan {{Japan-river-stub