New federal population figures released Thursday show the nation’s youngest county is in the Northwest, and not in an urban area. Madison County, Idaho is in the midst of eastern Idaho's potato country.
To give a comparison, the median age of the U.S. is almost 38 years old. The median age of Madison County is 23. That’s the lowest in the country and there’s one big reason: Madison County is home to Brigham Young University-Idaho.