"The Rivers Run Red" - that's the theme of this sort-of western set on the Paraguay-Argentina border (formed by the River Parana, referred in the title).
The story concerns peons recruited to go upstream to the frontier, "Alto Parana", to work on an estate - and their subsequent exploitation and brutalization. The scenes are more harshly realistic than in US movies (especially from 1952), and a good reason to see the film if you can find a copy.
Since this part of Argentina is culturally Paraguayan, we are treated to quite a bit of Paraguayan harp music and dancing. There's even a saloon called El Guarani where we see the harpist playing blithely while mayhem takes place around him. This includes one of the best barroom brawls ever found in a western - you'll just have to see it. The rhythm of the film rises toward a violent conclusion.
My version doesn't have subtitles, so I couldn't tell what work was in progress - clearing land? ...cutting branches for fodder or mate? The movie is good enough to deserve a proper release.
The acting is excellent - I couldn't find a false note anywhere. I gather the country was then in the fiercest stage of Peronism, so the movie was probably a heroic labour of love for all the actors in it.