Steller's jay was formally described in 1788 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae.

[2] Gmelin based his account on "Stellers crow" that had been described in 1781 by the English ornithologist John Latham in his book A General Synopsis of Birds.

Latham had examined a specimen belonging to the naturalist Joseph Banks that had been collected in Nootka Sound, Vancouver Island off the Pacific coast of Canada.

The head is blackish-brown, black, or dark blue, depending on the subspecies of the bird, with lighter streaks on the forehead.

[11] The genus Cyanocitta is part of the passerine family Corvidae, which consists of the crows, ravens, rooks, jackdaws, jays, magpies, treepies, choughs, and nutcrackers.

Steller's jay occurs in most of the forested areas of western North America as far east as the eastern foothills of the Rocky Mountains from southern Alaska in the north to northern Nicaragua in the south[11] completely replacing the blue jay prevalent on the rest of the continent in those areas.

In the northern end of its range it appears to be spreading from coastal Southeast Alaska across the Coast Mountains into southern Yukon Territory.

Steller's jay's diet includes a wide range of seeds, nuts, berries and other fruit.

[13] Acorns and conifer seeds are staples during the non-breeding season; these are often cached in the ground or in trees for later consumption.

They exploit human-provided food sources, frequently scavenging picnics and campsites, where it competes with the Canada jay.

Similar in construction to the blue jay's nest, it tends to be a bit larger (25 to 43 cm (9.8 to 16.9 in)), using a number of natural materials or scavenged trash, often mixed with mud.

Steller's jay is also a noted mimic: it can imitate the vocalizations of many species of birds, other animals, and sounds of non-animal origin.

In contrast, Steller's jays exhibit a longer latency to return to feeding when northern goshawks are seen rather than heard.

Steller's jays will then vary the production of their "wah", "wek", and mimic red-tailed hawk calls in response to different detection cues.