When a nomadic group is forced out of Prax, they retreat across the Vulture Country into the Genert Wastes. Vulture Country is about as bleak a terrain as it comes.
Beyond Vulture Country is the Wastes, a truly arid region that gets between 0 and 25 cm of rain a year. Sand storms and copper winds are common, and there are areas larger than Dragon Pass covered in cactus desert. And there are worse areas – the Copper Sands, Tunneled Hills, Greydust, and the Demons Quarter have a fearsome reputation even by nomad standards.
But there are grasslands here as well. Most are good only in the (comparatively) wet season, but a few are good year round. Those are mostly found around the Krjalki Bog, and must be defended against the Chaos monsters of the bog.
These are the lands that the exiled nomads are forced into. The Wastes force their inhabitants to sacrifice all that is not necessary for survival, including many gods. Invader cults such as the Lightbringers and Yelmalio lose much of their importance, while Storm Bull and Waha grow in significance.
In the Second Age, the tribes were exiled into the Wastes around 880 or so. In 924 their warriors emerged from the Wastes, led by Jaldon Goldentooth, but the tribes did not return in mass until 940, when Pavis had fallen. More recently, the Bison and Impala were mostly forced into the Wastes after 1610 but returned in 1625 with the fall of New Pavis to Argrath.
Now for outsiders, the Wastes are completely inhospitable. Most Lunar leaders believed that nomad bands that entered the Wastes were gone – sacrificing themselves in some bizarre mass suicide ritual. Many Sartarites and Sun Domers shared this belief. Others were aware that the nomads could survive in the Wastes, but discounted the possibility that large numbers could do so. The Issaries cult knew that it was possible to cross the Wastes thanks to the Desert Trackers, and the Desert Trackers do enter into the Wastes to trade with the nomads.