Santa Cruz River, which the Iemisch allegedly swam down, has its source at Lake Argentino (50°14’ S, 72°25’ W); a vast lake with a surface area of 1.415 km2 [546 sq. mi.]).
See a map of the area and the river's course Here.
Argentine explorer Francisco Moreno, who had visited (and discovered) the lake in 1877, noted an Aonikenk superstition regarding evil lake spirits: “The Indians have told me about the lake’s walichus: one, awe-inspiring, immensely large, comes and goes in its waters when men go to drink in them”.
Moreno did not believe that the natives meant that some evil animal or being lived in the lake; he thought that their superstition referred to the icebergs calved from the glaciers that float in the lake.
Copyright © 2007 by Austin Whittall
But he could have been mistaken; perhaps the myth referred to some gigantic lake creature. The coming and going of the walichu’s implies volition, something animals have but icebergs lack.
Lista reported in 1892 that the Aonikenk had told him that by the Santa Cruz River at a site known as Cahuerne (in their language, Carhuern’n means place of the malefic spirits”), now known as Sierra de los Baguales – Wild Cattle Hills; lived “four legged monsters that once, according to tradition, devoured a whole family”.
 Moreno, F., (2007 a). Op. Cit. pp. 101.
 Martinic M., (1995). Op. Cit. pp. 353-4.
Lista, R., (1896). Fragmento del segundo viaje a los lagos del Payne (Andes Australes). B. Aires. Anales de la Sociedad Científica Argentina, v. xli:336.
Further reading on the: Santa Cruz River basin.
Copyright 2009 by Austin Whittall ©