A private client brought to ICA this feather halo war bonnet that had been presented to South Dakota historian Joseph Harper Cash (1927-1991). Prior to surface cleaning the bonnet, Textile Conservator Jane Hammond used a tapestry needle with a rounded tip to separate and lift compressed clumps of barbs on the down feathers. The flight feathers were cleaned by vacuuming through fiberglass screening or dusting into the nozzle of a vacuum microtool. Detached feather bundles were secured. Missing rawhide cording was replaced with dampened strips of Japanese paper folded and compressed to resemble hide strips. Hammond, with the assistance of ICA mount-making staff, constructed a display mount to appropriately support the bonnet and a vitrine base of oak wood, stained with an ebony finish, and the plywood base of the vitrine was covered with cotton felt and museum fabric.