Biologically important areas (BIAs) for cetaceans were defined by compiling the best available information from scientific literature (including books, peer-reviewed articles, and government or contract reports), unpublished data (sighting, acoustic, tagging, genetic, photo identification), and expert knowledge. This information was then used to create written summaries and maps highlighting areas shoreward of the U.S. Exclusive Economic Zone that are biologically important to cetacean species (or populations), either seasonally or year-round. This collection contains the data displayed by BIA type, including feeding, migratory corridors, reproduction, and small and resident populations. Feeding BIAs include areas and months within which a particular species or population selectively feeds. These may either be found consistently in space and time, or may be associated with ephemeral features that are less predictable but can be delineated and are generally located within a larger identifiable area. Migratory Corridor BIAs include areas and months within which a substantial portion of a species or population is known to migrate. Reproduction BIAs include areas and months within which a particular species or population selectively mates, gives birth, or is found with neonates or other sensitive age classes. Small and Resident Population BIAs include areas and months within which small and resident populations occupy a limited geographic extent.