This article may be expanded with text translated from the corresponding article in Japanese. (April 2022) Click [show] for important translation instructions. View a machine-translated version of the Japanese article. Machine translation like DeepL or Google Translate is a useful starting point for translations, but translators must revise errors as necessary and confirm that the translation is accurate, rather than simply copy-pasting machine-translated text into the English Wikipedia. Consider adding a topic to this template: there are already 3,164 articles in the main category, and specifying|topic= will aid in categorization. Do not translate text that appears unreliable or low-quality. If possible, verify the text with references provided in the foreign-language article. You must provide copyright attribution in the edit summary accompanying your translation by providing an interlanguage link to the source of your translation. A model attribution edit summary is Content in this edit is translated from the existing Japanese Wikipedia article at [[:ja:十勝川]]; see its history for attribution. You should also add the template ((Translated|ja|十勝川)) to the talk page. For more guidance, see Wikipedia:Translation.
Tokachi River
十勝川, Ainu: Tokapci
Iwamatsu Dam in Shimizu (September 2007)
Native nameTokachi-gawa  (Japanese)
DistrictKamikawa, Nakagawa
MunicipalitiesShintoku, Toyokoro
Physical characteristics
 • locationShintoku, Hokkaidō, Japan
MouthPacific Ocean
 • location
Toyokoro, Hokkaidō, Japan
 • elevation
0 m (0 ft)
Length156 km (97 mi)
Basin size9,010 km2 (3,480 sq mi)
 • average71 m3/s (2,500 cu ft/s)

Tokachi River (十勝川, Tokachi-gawa) is a river in Hokkaidō, Japan.


In 1820, the explorer Takeshiro Matsuura (松浦 武四郎) proposed "Tokachi" as the name of the surrounding Tokachi Province, with each character corresponding to a Japanese homophone. The province was named after this river, which in turn was derived from the Ainu language word "tokapci".

Although the exact origins of "tokapci" were unknown, Hidezo Yamada, an Ainu language researcher, proposed these origins:

Coordinates: 42°41′42″N 143°39′58″E / 42.6950°N 143.6661°E / 42.6950; 143.6661