This image shows waves lapping the shore of the ‘tip of the thumb’ area of the lower peninsula of Michigan, near Pointe Aux Barques, the northernmost point of the ‘thumb’.
The description states:
MICHIGAN THUMB SCENERY
Breakers at Pointe Aux Barques in the tip of the Thumb.
–The name means Point of Small Boats, apparently a reference to the shallow waters and reefs that pose a hazard to larger ships approaching the shore in the area. There is a lighthouse to advise passing ships of the danger. The object on the lake in the background is a passing ship.
This image is dated 1955.