Ulkayak

The Ulkayak is a river in Kazakhstan. It has a length of and a catchment area of.
It is one of the rivers of the southern part of the Turgay Depression, belonging to the Irgyz -Turgay ecoregion. It flows across the Zhangeldi District of the Kostanay Region, Kazakhstan. There are historical Kazakh sites in the valley of the Ulkayak.

Course

The Ulkayak is formed at the confluence of rivers Zhantai and Tolybai. The river flows first southwestwards across steppe territory within a flat valley. It cuts across some gorges along its course, the longest of which is. Towards its last stretch its valley widens and the river meanders heading roughly southwards. Finally it flows into the Kyzylkol, a salt lake which is connected with the Turgay through a system of lakes linked by channels. The water of the river is fresh, but it turns brackish in the summer, when the river dries in stretches and its flow almost stops.

Tributaries

The long Kabyrga and the long Karabutak are the main tributaries of the Ulkayak. The river freezes yearly between early November and late March. Its main food is snow.