The peoples of the Northwest Coast traded extensively among themselves and with communities in the interior. A large proportion, if not most, of Chinook Jargon vocabulary was taken from Chinook proper. It is thought that Chinook Jargon predates indigenous contact with Europeans and European Americans, which was initiated in the 18th century pursuant to the fur trade. The English (English language) and French (French language) elements in the pidgin's lexicon (vocabulary) seem to be primarily borrowings into Chinook Jargon after it had become widely adopted as the lingua franca for the fur trade.

Chinook Jargon dispensed with some polysynthetic aspects typical of the grammar of American Indian languages—that is, with the practice of combining several small word elements (none of which may be used as a free, or stand-alone, word) to form a complex word. For example, Chinook Jargon provided free pronouns for subject and object without any corresponding affixes to identify tense, gender, possessive, or other such variables, so that “he spoke” would be translated as yaka wawa, where yaka indicated third person singular (and was occasionally used for the plural form as well) and could mean ‘he,' ‘him,' ‘his,' ‘she,' ‘her,' or ‘hers' and wawa was defined as ‘to speak,' ‘speech,' ‘word,' or ‘language.' The same phrase would be translated in Chinook proper as I-gikim ‘he spoke.' Chinook Jargon also partially adopted the subject–verb–object (SVO) syntax that is typical within the verb complex (the verb and its affixes) in northwestern American Indian languages, as in ukuk man tšaku ‘that man came.' This is different from the VSO pattern in which noun phrases and the verb complex are sequenced in Chinook proper, as in áiuu i-qísqis ‘the blue jay went on' (literally, ‘he went on 【masculine singular】-blue jay').

Indigenous, European, and European American traders helped spread Chinook Jargon from areas around the Columbia River north to southern Alaska and south almost to the present-day California border. In the late 19th century, however, English started supplanting Chinook Jargon as a lingua franca. By the early 20th century, Chinook Jargon was virtually extinct in the United States (with the exception of a few words used locally as slang), but it survived a few decades longer in British Columbia.