Lake Ulug-Kol is located in the northern part of the mildly hilly, forestless Karasuk steppe, 40 kilometers west of the city of Chernogorsk.
The lake is of oval shape, measuring 4.5 kilometers in length and up to 2 kilometers in width. In the northern part, there is a triangular peninsula that juts out into the lake for almost a kilometer. The maximum depth is measured 2 metres in the eastern half.
Lake Ulug-Kol is fed mainly by atmospheric precipitation and underground runoff from the lake valley. During wet seasons, the lake is usually water-abundant, in dry years it significantly decreases in size and backs down from the shores. The shores are low, swampy, sandy-muddy for a considerable distance. The northern shore is significantly swampy. The bottom of the lake is flat and gentle.
There is the largest habitation of the oystercatcher in Central Siberia, listed in the Red Book of the Russian Federation. Many species of birds listed in the Red Book stop over here in spring and autumn during their migrations. In August there are around 5-8 thousand individuals of waterfowl accumulated on the lake. During the spring and autumn migrations, the site is an intermediate stage for the passage of thousands of ducks, geese, swans and especially waders.
Lake Ulug-Kol is a key ornithological area of international status, being a part of the wetlands included in the Perspective List of the Ramsar Convention.
The lake is part of the Nature Reserve “Khakassky” and also a part of the site “Kamyzyak Steppe with Lake “Ulug-Kol”