| Category | Rivers |
| Continent | Brucrumus |
| Region | Aerie of Dragons |
| Alias | Ice Vein |
| Map | Iiz Sostrah River |
Iiz Sostrah is a cold river of the Aerie of Dragons. It begins off the northern cliffs of Inzurakthol. It flows north past the head of the Siginzad valley. Going further north the river is fed by the waters flowing out of Minulkazar. Iiz Sostrah passes north of Filmah Feykro where it then merges with Zal Rath, and courses west until emptying into the Sea of Mourning.