On maps, the eastern quadrant of the desert is called the Deadly Desert, while the other three quadrants of desert are called the Shifting Sands, the Impassable Desert, and the Great Sandy Waste.
The desert was originally described as dangerous as any natural desert but no more. Indeed, in The Marvelous Land of Oz, Mombi tries to escape through it in the form of a griffin and Glinda chases her over the sands. In Ozma of Oz, it has become a magical desert with life-destroying sands and noxious fumes, a feature that remained constant through the rest of the series.
Anyone who sets foot into the sand of any of these deserts turns into sand themselves. The desert is used as a literary device to explain why Oz is essentially cut off from the rest of the world and the rest of Nonestica. However, it has been crossed several times by people from within Oz and from the outside world, with applied ingenuity, with magical assistance, or through unusual natural phenomena.
In ppThe Wonderful Wizard of Oz[[, Dorothy Gale is carried into Oz in her house by a cyclone and back over again by her magic shoes, which fall off during her flight and are lost in the desert. Also, the Wizard of Oz originally arrived in Oz by a circus balloon (which he implies functioned by a gas lighter than air, rather than hot air), and years later leaves Oz in a hot-air balloon of his own design.
In The Scarecrow of Oz, Trot, Cap'n Bill, and Button-Bright flew over the desert carried by birds and led by Flipper the Ork.
In The Magic of Oz, Kiki Aru transformed himself into a bird and flew over the Deadly Desert from the Land of Oz, exploring the various countries of Nonestica.
In Kabumpo in Oz, a giant Ruggedo hopped right over the Deadly Desert and ran back to his mountain in the Land of Ev after Princess Ozma's palace got stuck in his hair spikes. In the same book, Kabumpo, Peg Amy, Pompadore, and Wag crossed over the Deadly Desert on a runaway country.
In the film Return to Oz, Dorothy Gale crosses the edge of the Desert by stepping upon stones. Later, the pack of Wheelers working for Mombi fail to get across the Deadly Desert in pursuit of Dorothy and the Gump, who cross the desert to reach the Nome King's mountain. Six of the Wheelers fall into the desert and are subsequently turned into sand and killed. The seven remaining Wheelers later return with Princess Mombi and cross the desert through the tunnel dug underneath the desert to reach the Nome King's mountain.