My girlfriend lives in Oklahoma - it is not a holiday there.
I am amazed that something we (when I was in college) fought so hard for is taken for granted as "just another 3 day holiday" by some and yet still not observed in many states.
As an aside...my mom got a cd as a favor from a friends birthday party - she didn't realize that Stevie Wonders "Happy Birthday" was originally written in support of establishing MLK's birthday as a holiday. I made her listen to the words....she doesn't listen to "secular" music and never knew where that "new version" of Happy Birthday came from.