The Chulym is formed by several tributaries in the Toyskoye Zaymishche (Russian: Тойское Займище) and Troshinskoye Zaymishche (Russian: Трошинское Займище) swamps north of Baraba Steppe, some 100 kilometres (62 mi) northwest of Novosibirsk, at an elevation of 150 metres (490 ft). The river flows over the Baraba Steppe in a southwesterly direction, and flows through the lakes of Sargul (Russian: Саргуль), 34.6 square kilometres (13.4 sq mi), and Uryum (Russian: Урюм), 84.1 square kilometres (32.5 sq mi), before it finally terminates, at 106 metres (348 ft) elevation, in Lake Malye Chany (Russian: Малые Чаны – Little Chany), which is connected to Lake Chany through a short strait.
In its lower reaches the river is some 30 metres (98 ft) wide and 5 metres (16 ft) deep. Its main tributaries are the Suma River (left), and the Kargat River (right). Lake Itkul is one of the largest lakes of the Chulym floodplain.[2][3]