This image shows the narrow canyon leading to the Bingham Canyon Mine, an open pit mine that covers the entire background of the photo.
The description states:
BINGHAM CANYON AND COPPER MINE, UTAH
The most unusual town in the world, Bingham Canyon is one street wide and three miles long. Its single street leads up the floor of the canyon and the homes and business buildings hug the steep mountain sides. In the background tower the terraces of Bingham Copper Mine, largest open-pit copper mine in the world.
–This card has a small pouch of copper ore attached to the side, much the same as the salt samples commonly attached to similar postcards. This card is believed to date from the 1960s.