Alberta could simply become the 51st US state.
Stated by: Discussed by some Alberta independence advocates
Summary
Becoming a US state is not a shortcut around independence; it would require Alberta to secede from Canada first, then be admitted by the US Congress under its Constitution. Even then there is no guarantee of full statehood rather than a lesser territorial status, and no binding framework exists for it. Commentators describe the path as possible in theory but highly uncertain, with outcomes ranging from a state to a Puerto Rico-style territory.
Evidence
Becoming part of the US would require Alberta to first separate from Canada and then be admitted under the US Constitution; there is no guarantee of statehood over a lesser territorial status.
The Conversation (what if Alberta voted to separate) (opens in a new tab)
Commentators describe a US-aligned Alberta as a landlocked entity with little leverage, where territory status is as plausible as full statehood.
Canadian Centre for Policy Alternatives (opens in a new tab)
Analysis notes that as a US state Alberta would trade an internal border with Canada for an international one, complicating, not solving, pipeline access.
The Globe and Mail (51st state analysis) (opens in a new tab)