This image shows a high aerial view of the dam used to create the Lake of the Ozarks, Bagnell Dam. It is located on the Osage River. It is named after the neaby town of Bagnell, which in turn was named after the man who founded the town.
The description states:
AERIAL VIEW OF BAGNELL DAM AND THE LAKE OF THE OZARKS
Serving the useful purpose of supplying the midwest with both power and recreation.
–The dam was completed in 1931, its construction providing essential employment during the early days of the Great Depression. More views of this dam were posted here. This card likely dates to the 1950s.