Sentence:  According to Ponomarev's calculations, the <WSD>Kama</WSD> in the 1890s annually supplied the Volga with up to 850000 logs, of which about 250000 came from the Chusovaya, about 250000 from the Vyatka and its tributaries, 150000 from the Belaya,.... 
Meaning of the word marked with <WSD> tags:  A major river in Russia, the longest left tributary of the Volga.