[1] The river flows for 159 kilometres (99 mi) through Sonkovsky District of Tver Oblast and Nekouzsky and Breytovsky Districts of Yaroslavl Oblasts of Russia before entering the Rybinsk Reservoir near the large village of Breitovo.

In the Middle Ages the valley of the Sit belonged to a branch of the princely House of Yaroslavl.

The princes of the Sit', or Sitsky, joined the service of the Grand Dukes of Muscovy in the 15th century.

[3] The source of the Sit is in the north of Sonkovsky District, close to the village of Saburovo.

In the early 20th century the valley of the Sit River was home to the Sitskari (ru), an ethnic group of short fair-haired people speaking a Northern dialect of the Russian language.