Making a rather large jump from 13 to 7, Ravalli County has seen a tremendous increase in population since 1930. With a 2010 population of 40,212, it is one of two counties that would make the jump into the top ten if license plate codes were reassigned today. Ravalli County had a population of 10,315 in 1930, according to the U.S. Census Bureau.
7. Ravalli County