The river on which they were traveling had to be Amu Daria. People were put on large barges, many did not survive this flight (diseases, poor nutrition). The end of the flight was in Farab.
By the way my ggfather Jozef Zaremba and one of his daughters were sent to one of the spec-villages in Archangielsk Oblast in February 1940. They lost their lives on the Amu Daria River.