◆ documented
The Kalaus in the Book of the Great Map
The Book of the Great Map names the steppe river Kalaus in a single passage both “Kulauz” and “Kalauz”. It is the earliest known mention of the river in whose upper reaches the Khoper Cossacks lived from 1777 to 1825.
- [◆ Kniga Bolshomu chertezhu, 1627, via Wikisource]