This is the largest North American grebe. It is 55–75 cm (22–30 in) long, weighs 795–1,818 g (1.75–4.01 lb) and measures 79–102 cm (31–40 in) across the wings.[[|]][[|]][[|]] It is black-and-white, with a long, slender, swan-like neck and red eyes. It is easily confused with Clark's Grebe, which shares the same features, behavior and habitat, and hybrids are known.
The Western Grebe has black around the eyes and a straight greenish-yellow bill whereas the Clark's Grebe has white around the eyes and an up-turned bright yellow bill. The downy young of Western are grey; Clark's downy young are white.