Final answer:
Minnesota is the least populated out of all the western states.
Step-by-step explanation:
The state that was by far the least populated out of all of the western states is Minnesota.
Maine, which is located in the northeastern region of the United States, is the least populated state overall. However, when considering the western states specifically, Minnesota stands out as the least populated.
Minnesota has a population density of about 71 residents per square mile, which is much lower than the other western states mentioned in the question.