a river in the Mari ASSR, partially along the border with the Tatar ASSR; left tributary of the Volga (empties into the Kuibyshev Reservoir). Length, 204 km; basin area, 6,450 sq km. The upper Ilet’ has low-lying shores; toward the mouth the shores become higher, but in many places there are swamps. The river is fed primarily by melted snow. The river freezes in mid November and thaws in mid-April. The Ilet’ is used for floating timber and is navigable in its lower reaches.