Just WHERE is “Up North” in Michigan?

It's almost the 4th of July. Almost everybody in Michigan has, or will soon be, headed "up north". But where does "up north" start? My dad grew up in East Lansing, so, growing up, I heard a lot of stories about the U.P. and Mackinac Island, but I'd never heard the term "up north", until I moved here 16 years ago. Since then, I've developed MY idea of where that is, but....

ClickOnDetroit brings up a good question: WHERE exactly does "up north" start in Michigan?

They have arrived at five possible answers. I think we only need three. Is it:

1. North of a line drawn from Grand Rapids to Flint? (That would put everything north of St.Johns, "up north")

2. Past a line drawn starting at the top of the thumb? (Making everything past Clare, "up north")

Or - 3. The Mackinac Bridge? (Seriously?)

My answer would be: past the thumb. I think the whole look of Michigan starts to change on 127, once you get north of Clare. It just starts to look "up north" to me at that point. But, what do YOU think?

Here's the article, with a chance to vote on your choice.