This image shows the Port Austin Lighthouse, located just off the northern tip of the ‘thumb’ of Michigan’s lower peninsula, where it protects ships from a dangerous reef.

The L.L. Cook Co., Milwaukee, WI
The description states:
Michigan Thumb Scenery
Port Austin Lighthouse, Port Austin, Michigan
–The lighthouse was constructed in 1878 and has been regularly updated since then. It is now maintained by a private restoration group, and runs off of solar power.
This card is dated 1957.