The white morph of the Snow Goose is similar to widely-escaped domesticated barnyard goose. Note that the Snow Goose has black primaries and a distinctive bill pattern. Domesticated geese have white primaries and, often, an entirely orange bill. White morph Ross's Goose is extemely similar to the white morph Snow Goose. The Ross's Goose is smaller with a stubbier bill without the black patch on the mandibles. It also appears rounder-headed with a shorter neck. Immature white morph Snow Goose is darker-backed than the immature white morph Ross's Goose. The rare blue morph of the Ross's Goose can be separated from the similar blue morph of the Snow Goose by the same structural characteristics already mentioned. Hybrids between Ross's and Snow Geese have intermediate characteristics. The immature blue morph is similar to the immature White-fronted Goose but has dark legs and bill.
Length and wingspan from: Robbins, C.S., Bruun, B., Zim, H.S., (1966). Birds of North America. New York: Western Publishing Company, Inc.