While we're talking about Ozian mountaintops communities, why don't we take a look at Mount Munch, a mountain with steep sides a saucer-shaped top in the northeastern Munchkin Country, bordering on the Deadly Desert. The mountain first shows up on the map on the Tik-Tok of Oz endpapers, and first enters into a plot in The Tin Woodman of Oz. Near its foot lies the home of Nick Chopper's former lover Nimmie Amee and her husband Chopfyt, and the nearby plains are the location of the Swynes' farm. These pigs, Professor Grunter and his wife Squealina, are the parents of the Nine Tiny Piglets that the Wizard of Oz uses in his tricks. And in the next book, Magic, we learn what's on top of Mount Munch. Not surprisingly, it's an isolated civilization, the people being known as Hyups.
We only learn the names of three Hyups in the book, and they are all from the same family, the Arus. Bini Aru used to be a sorcerer, and came up with a way to perform any transformation just by saying a single word. Baum apparently spelled the word a few different ways in his first draft of the text, but it was spelled PYRZQXGL in the published version. It's important to pronounce it just the right way, however, and of course Baum never tells us what that pronunciation is. When Ozma outlawed magic, Bini destroyed all of his tools, but considered the word too good to give up. So he wrote it and the correct pronunciation on a floorboard. When Bini and his wife Mopsi, known for baking huckleberry pies, were away at a festival, their sullen teenage son Kiki (yeah, I know that's not usually a boy's name, but it apparently is among the Hyups) discovers the floorboard, and uses the transformation word to visit some of the countries surrounding Oz. In Ev, he runs into Ruggedo, the former Nome King, who convinces him to help out in his latest plan for the conquest of Oz. Kiki doesn't trust the Nome, for good reason, but he does go along with Ruggedo's scheme. They argue, however, and the Wizard of Oz learns the magic word and turns the two conspirators into nuts. When he restores them, he has them drink of the Water of Oblivion, and that's the last we see of the boy in the canon. We can only imagine how the elder Arus reacted to their missing son.
Actually, that idea forms the background for the plot of the short story "Much Ado About Kiki Aru," which appeared in the 1986 Oziana. In the story, Bini goes out to search for Kiki, and eventually finds him and brings him back to Mount Munch. The same tale also gives the origins of the magic word, and it stops working by the end. That would explain why the Wizard never uses it in later books, even when it would come in handy. On the other hand, the apocryphal Invisible Inzi, Glass Cat, and Unknown Witches all have the word still working.