Throughout New Guinea, bird feathers have long played an important part in dance costumes and personal adornment, and they continue to do so. In the East Sepik Province, feathered dance costumes of extraordinary complexity and height were recorded in the early twentieth century in villages on the Keram and Ramu Rivers, the Murik Lagoon, and Hansa Bay. A different ceremonial use of feather mosaic arrays on wooden supports existed in villages along the Keram River and are the subject of this study. Very little contextual information was recorded when these assemblages were collected between 1913 and 1936, but recent research indicates that panel-shaped feather mosaics were arranged into large-scale assemblages inside the men’s ceremonial houses for the initiation ceremonies of young men. As highly charged and powerful objects, they bridged the world of the living with that of the ancestors, a visual aid to access complex myths and stories that would provide the spiritual foundation for every young man’s education. While clearly related, the exact function of paddle- shaped feather mosaics collected in the same region still eludes us.