I've lived in SLC all my life and the beauty of the women here is normal for me but still blows me away. I'm married to one of them but I kid you not, 50% of the women on my street are all super hot moms in their 30's.
BYU in Provo (35 miles or so south of Salt Lake) regularly takes the Hottest Coed population and the University of Utah in Salt Lake is just as good in my opinion. And those hot coeds stay hot into their 40's.
It comes from the mormon culture that your body is a temple, treat it like one. Meaning eat healthy, stay fit, no drugs/alcohol, etc. Seems to work out pretty good for them.