is a river in

Hokkaidō is the second-largest island of Japan and comprises the largest and northernmost prefecture, making up its own region. The Tsugaru Strait separates Hokkaidō from Honshu; the two islands are connected by railway via the Seikan Tunnel. The ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

. 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 rang ...

in the Hidaka Mountain range, and flows across

Rumoi Subprefecture is a Subprefectures of Hokkaido, subprefecture of Hokkaido, Hokkaido Prefecture, Japan. As of 2011, it had a population of 52,627 and an area of . The population density of the subprefecture, 13 people per km2, is very low compared to the rest o ...

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, it ...

. The

mouth A mouth also referred to as the oral is the body orifice through which many animals ingest food and animal communication#Auditory, vocalize. The body cavity immediately behind the mouth opening, known as the oral cavity (or in Latin), is also t ...

of the Rumoi River is in the city of

Rumoi 290px, Rumoi city hall 290px, central Rumoi is a city in Rumoi Subprefecture, Hokkaido, Japan. , the city had an estimated population of 18,132 in 10519 households, and a population density of 61 people per km2. The total area of the city is . T ...

References

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