51-58 cm (20-23") Common along Pacific Coast in winter and inland lakes in summer where it nests in large colonies on prairies; casual on east coast in winter. Crow-sized gull. White head, underparts and tail; dark gray mantle; black wing tips with white spots; dark eyes; yellow bill with black- and-red spot on lower bill; greenish-yellow legs.
Winter adults similar but head streaked in brown.
Similar Ring-billed Gull has a black ring around bill.