An initial trace element study of selected pyroxenes from the 1912 Katmai volcanics was conducted using combined electron microprobe and secondary ion mass spectrometry techniques. Trace element distribution between pyroxene and melt over a wide range of melt composition (58.5--77 wt.% SiO2) is dominantly controlled by pyroxene crystal chemistry. Most other factors (melt structure, temperature) appear to be minor. In addition, major and trace element zoning patterns suggest an episode(s) of magma replenishment of the volcanic syb-system with more ''primitive'' magmas. This may correspond to events within the complex Novarupta-Trident-Mount Katmai magma plumbing system.