Grays (Eschrichtius robustus) are baleen whales. Adult gray whale length is 39-46 feet, with the largest recorded measuring a little longer than 49 feet. Weight is 15-39 tons. A gray whale can live approximately 70 years.

Gray whales spend April-November in their Arctic feeding grounds, and December-April in Mexican breeding areas. Between October and February the species migrates south along the West Coast, returning north between February and July. This round trip migration of 7,400-12,400 miles every year is believed to be the longest of any mammal.

This species is a coastal cetacean, usually seen over the continental shelf. During migration most animals pass within about a mile of the shoreline, and gray whales occasionally come into Puget Sound.

The gray whale is unique among cetaceans as a bottom-feeder that rolls onto its side, sucking up sediment from the seabed. Bottom-dwelling organisms live in this sediment, and stay in the baleen as water and silt are filtered out. Gray whales feed in shallow waters, usually 150-400 feet deep. Adults can consume 1-1½ tons of food per day during peak feeding periods.