This image shows the largest body of water in Yellowstone National Park, also called Yellowstone Lake. The lake is situated at over 2200 meters above sea level.
The description states:
7,731 feet above sea level and covering 139 square miles, Yellowstone Lake is the largest body of water in North America at so great an altitude. Its crystal blue waters abound with native trout.
–This card likely dates from the 1950s.