Uncle Scrooge comic

Hi! I have been looking for an old comic of Uncle Scrooge. It is quite old, before 1970 at least. Uncle Scrooge sends Donald and his nephews to a desertic town in the middle of nowhere (do not remember why, but the town was called "amusing valley" or something like that). They reach that place by train, traveling with the cows, courtesy of Scrooge, and once they arrive they notice that it is all a desert, and that the "town" is just an old crumbling house. Looking for water Donald happens to find some gold nuggets, and by working that mine he ends up being richer than Uncle Scrooge, and visits Scrooge at his Money Bin wearing an expensive tuxedo, with jewels and all. At the end of the story Scrooge discovers that such mine was within his own lands, and reclaims Donald's fortune. I thought it was one by Carl Barks', but so far I have not been able to find it.