Google says the two letter abbreviation for Michigan is CA
google.comMichigan -> CA https://archive.ph/i3o3N Montana -> DC https://archive.ph/vo5Vo Nevada -> GA https://archive.ph/ZW0jR
It looks like it's due to weird table structure on the FAA's website, which Google is returning in their answer box. That being said, Google should know better.
https://www.faa.gov/air_traffic/publications/atpubs/cnt_html...