Passage: It originates from Mount Ishikari in the Daisetsuzan Volcanic Group and flows through Asahikawa and Sapporo. Major tributaries of the river include the Chūbetsu, Uryū, Sorachi and Toyohira rivers. Until 40,000 years ago, it flowed into the Pacific Ocean near Tomakomai. Lava from the volcanic Shikotsu mountains dammed the river and moved its mouth to the Ishikari Bay.

Question: Where does the river originate from?
Mount Ishikari