The ornithological collection of the National Fish and Wildlife Forensic Laboratory in Ashland, Oregon includes over 6,800 bird skin and loose feather specimens. These are essential reference material for the morphological identification of avian evidence in wildlife crime investigations by the U.S. Fish and Wildlife Service. In the summer of 2020, these specimens were moved from several locations and installed in a new building dedicated to the laboratory's bird, mammal, and herpetological collections. Following installation in the new building, a severe outbreak of mold was discovered in many of the cabinets containing bird specimens. This paper reports on the likely cause of the mold outbreak and the actions taken to control it, preserve the specimens, and prevent future outbreaks.