A recent study (yes one of those) ranked all 50 states by looking at four different categories of stink . . .
how dirty the air is
how many landfills there are
dental health, as a measure of bad breath
and population density to estimate how much B.O. you have to deal with.
Colorado-Despite Greely-actually not too smelly-- Close to the Middle- #18
...But With Everyone Moving Here- I am sure we can smell almost as bad as California in No Time.