Small depressions on the upper jaw each contain a lone stiff hair, but are only visible on close inspection.
Its head's ventral surface lacks the numerous prominent furrows of the related rorquals, instead bearing two to five shallow furrows on the throat's underside.
In May 2013, a gray whale was sighted off Walvis Bay, Namibia.
Scientists from the Namibian Dolphin Project confirmed the whale's identity and thus provides the only sighting of this species in the Southern Hemisphere.
In January 2011, a gray whale that had been tagged in the western population was tracked as far east as the eastern population range off the coast of British Columbia.