Well we`re right up there.  It all depends on what your measurements of "corruption" are.

http://www.westernjournalism.com/corrupt-states-america/

In just a cursory look..  for instance,.. who had the most corruption convictions per capita over a given time span?
; http://www.westernjournalism.com/corrupt-states-america/  
That one says we`re number three.  

Like diapers, I guess it depends on your view on what`s considered "corruption". 
Is stealing BILLIONS in value from the people of Alaska through illegal gerrymandering and conflicted votes, that affected the policies and constitutional imperatives of this state, corruption?...   I would say so, wouldn`t you?