This image is an illustration of the Juniata Bridge, or the Lewistown Road Bridge, which crosses the Juniata River in Lewistown, Pennsylvania.
There is no description on the back of this card.
According to the link above, this bridge was completed in 1924 as a replacement for an older truss bridge, and was in turn replaced in 1989. The mills in the background were part of the large complex of factories operated by the American Viscose Corporation, which was the largest producer of rayon in the early 20th century and the first to make artificial silk.
This card was used and is dated 2 August 1937.