You said Utah is out. Arizona is also out (any airport is in heat). Wyoming and Montana don't have the airports. Nevada is out, except for maybe Reno. Don't know much about Washington or Oregon but Spokane might be a option. I don't like Denver, but that could make sense. Idaho you have limited it to Boise. There are some good California options, but I am not sure how the cost would be around Sacramento.

I doubt it is a popular choice, but for me the answer would be Santa Fe New Mexico area. Decent size, but smaller feel. Albuquerque has a good airport. Great weather. Good out doors stuff.