The Bogen (Kazakh: Бөген Bögen, Russian: Бугунь Bugun) is a river in Baydibek and Otyrar districts, Turkistan Region, southern Kazakhstan.

In 1967 the Bogen Dam, with an area of 65 km2 (25 sq mi), was built on the river, connecting to the Syr Darya basin by means of the Arys-Turkestan Canal.

[1][2] The river begins at the confluence of the rivers Ulken Bogen and Bala Bogen, flowing from the southwestern slopes of the Karatau ridge.

In its last stretch it bends northwards and discharges into lake Kum-Kol, not reaching the Syr Darya channel.

Its longest tributary is the 164 km (102 mi) long Shayan (Шаян), now flowing into the Arys-Turkestan Canal.