In response to suggestions by a lunatic in the US Oval Office, Green Party Canada’s leader Elizabeth May suggested Canada should invite western states Washington, Oregon and California join B.C and split from Canada to form the ‘Cascadia’ eco-state.
(Note this article is from Jan 8, 2025 and Elizabeth May has since become co-leader of the party alongside Jonathan Pedneault).
You may have been thinking of the older movement to have a bunch of random parts of Nevada, Oregon, Washington, and California join up with Idaho. That one was a hell of a lot less consistent in what areas they wanted. Theres also the original proposal for what would become Utah which included lands as far away from Utah as San Bernardino and LA.