The Chusovaya () is a river flowing in Perm Krai, Sverdlovsk Oblast and Chelyabinsk Oblast of Russia. A tributary of the Kama, which in turn is a tributary of the Volga, it discharges into the Chusovskoy Cove of the Kamsky Reservoir. The river is remarkable in that it originates on the eastern slopes of the Ural Mountains in Asia, crosses the mountains, and mostly runs on their western slopes in Europe. The Chusovaya River is widely used as a source of water. In particular, its water is taken from the Volchikhinsky Reservoir, , to the Verkhneisetsky Reservoir to supply the major city of Yekaterinburg. Fifteen smaller reservoirs are spread over about 150 tributaries of the river. There are numerous metal and coal mines along the Chusovaya, and the river was intensively used to deliver their production to the western Russia. However, industrial navigation nearly halted with the development of railways in the early 20th century. Chusovoy is the major remaining port on the river. The Chusovaya River is famous for its hundreds of large rocks located along the shoreline (see infobox image) which are the major tourist attraction of the area. Some rocks posed much danger to boats, especially during the spring thaw. They are generally called boitsy (, lit. fighters). Many of them have individual names and are protected by the state as natural monuments. Hydrography The basin of the Chusovaya River has an area of and an average elevation of . The river is (777 kilometres according to other sources) and has an average height gradient of 0.4 m/km. It has two sources: Poludennaya Chusovaya and Western (Zapadanaya) Chusovaya. The former originates in a swampy area in the north of Chelyabinsk Oblast and flows to the north. After , it merges with the Western Chusovaya, which starts at the Ufaley ridge. Then the river flows for about on the eastern slope of the Ural Mountains; here its width is . In the upper stream Chusovaya takes many tributaries and shows on its shores outcrops of crystalline shale, which were formed through the interaction of magmatic and sedimentary rocks. In the middle reaches, the river slopes have canyon-like character. Here the river cuts through several low mountain ranges, which tower above the riverbed as cliffs called boitsy. There are about 200 of them in the middle reaches and about 50 are protected by the state as natural monuments. Boitsy