The location of adult Pacific herring (Clupea harengus pallasi) near Auke Bay, Lynn Canal, Alaska, varied by depth and geographic area over 24 successive months during 1973–1975. From June through September, schools concentrated at 5- to 37-m depths where zooplankton was abundant and moderate currents were present in a stratified water column. The schools migrated from this area to wintering grounds in October when windstorms and sinking of cooling surface waters broke up stratification, and daylight and food abundance declined drastically. The schools remained near bottom in the deeper parts of the wintering grounds at 52-to 85-m depths into February or March when day length had increased, but temperatures and food abundance remained low. At this time the herring left the wintering grounds and moved up Lynn Canal to areas near spawning beaches. Pacific herring remained in these areas until water temperatures increased and plankton blooms appeared in late April and May at which time the fish moved into the shallows and spawned. By early summer the schools gradually concentrated again on the main feeding grounds.