Why Is the Lower Peninsula Shaped Like a Mitten — and Is the Whole State Really Two Pieces?

Two geography questions Michigan gets constantly, and they’re worth answering plainly.

First: yes, Michigan is genuinely two separate landmasses. The Lower Peninsula (the mitten) and the Upper Peninsula (the long arm reaching west across the top) don’t touch. They’re separated by the Straits of Mackinac, where Lakes Michigan and Huron meet. For most of the state’s history, the only way across was by boat or, in winter, a nerve-racking drive over the frozen straits. That changed in 1957 when the Mackinac Bridge — “Mighty Mac,” five miles long — finally connected the two. Michigan is the only state in the country split into two large pieces like this.

Second, the mitten shape: that’s not designed, it’s just luck of the glaciers. During the last Ice Age, enormous sheets of ice advanced and retreated across the region, and their lobes carved out the basins that became the Great Lakes. The shape of Lake Michigan on the west and Lake Huron (plus Saginaw Bay) on the east squeezed the land between them into — by pure coincidence — something that looks remarkably like a right-hand mitten, thumb and all. The “thumb” is a real region locals call the Thumb, and yes, it’s exactly where you’d point on your hand.

That mitten is so recognizable that Michiganders use their own hand as a map. It’s one of the few states you can give directions on using only your fingers.