Under Canadian constitutional law, Alberta or really any province for that matter just can't up and leave Canada on their own. If they actually wanted to leave legally, they'd need to amend the Constitution, and that means getting everyone to the table - Ottawa and all the other provinces. Treaty Nations/Indigenous rights must also be addressed. The Supreme Court of Canada’s 1998 Reference re Secession of Quebec ruled that unilateral secession is illegal. A “clear majority” on a “clear question” in a referendum would create a democratic obligation to negotiate in good faith, but actual separation requires amending the Constitution. The Clarity Act (2000) codifies this: secession “would require negotiations involving at least the governments of all of the provinces and the Government of Canada.” The standard amending formula for this (the 7/50 rule) generally requires approval by the federal Parliament plus at least 7 provinces representing 50% of Canada’s population. Some legal experts debate whether unanimity might be needed for something as fundamental as breaking up the country, but broad provincial consent is unavoidable. Treaties in Alberta (primarily Treaties 6, 7, and 8) are nation-to-nation agreements between First Nations and the Crown (i.e., the federal government of Canada), signed before Alberta even existed as a province. They are protected under Section 35 of the Constitution Act, 1982. If Alberta were to separate, it would definitely impact treaty rights - things like land use, hunting and harvesting rights, resource access, even borders. That's why any separation talks would have to seriously consider and protect Aboriginal and treaty rights. The Clarity Act actually calls this out as one of the major issues that has to be dealt with if there's any talk of secession.