Alberta (Canada) is 2.5 times larger than Colorado (USA).
Alberta is a province of Canada. With a population of 3,645,257 in 2011 and an estimated population of 4,082,571 as of January 1, 2014, it is Canada's fourth-most populous province and most populous of Canada's three prairie provinces. Wikipedia
Colorado is a U.S. state encompassing most of the Southern Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains. Colorado is part of the Western United States, the Southwestern United States, and the Mountain States. Wikipedia