Lennart von Post discovered by accident a small canyon near Degerfors in 1923 which he thought could be the elusive outlet. This came with time to be known as Svea River. Von Post collaborated initially with Munthe to study Svea River but their collaboration fell apart by 1927 over personal issues. The idea that the Svea River canyon was the outlet of the Ancylus Lake gradually lost ground by the works of Sten Florin, Astrid Cleve and Curt Fredén. In 1927 Cleve who was already "an outcast of the geological community" commented in an opinion piece in "Svenska Dagbladet" on a proposal of making Svea River a national monument. She supported the idea of protecting the area but criticized the established interpretation of Munthe and von Post. Munthe replied in "Dagens Nyheter" and the debate went over to a personal quarrel in two more newspaper letters in January 1928. Cleve outlined her ideas for Svea River and Ancylus Lake in detail in 1930 making an alternative and intricate theory involving tectonic movements. By 1946 she had changed mind as she then proposed an altogether different theory claiming the Svea River canyons and potholes formed by subglacial drainage and had nothing to do with the Ancylus Lake. Svea River was finally dismissed in 1981 when potholes there were found to predate the lake.