This is an aerial image of the Soo Locks, connecting Lake Superior and Lake Huron. It features a view of a bulk freighter exiting the locks along with other ships in the locks awaiting release.

The caption states:

THE SOO LOCKS
Sault Ste. Marie Michigan
Here, on the left, is the newest lock (Mc Arthur) next to it the oldest (Poe) next the Davis lock, then the Sabin lock. Then you see the power plant and St. Mary’s Rapids. In the distance, with a boat emerging, is the Canadian Lock, and then Sault Ste. Marie, Canada.

–The locks pass an average of 10,000 ships a year, even though the locks close in the winter.

This postcard is dated 1955.