This image shows some temporary garages and shelters for groups hoping to race on the Bonneville Speedway.
The description states:
BONNEVILLE SALT FLATS
WORLD’S FASTEST SPEEDWAY
View of a race car location, on the world famous Bonneville Salt Flats. To the northeast of Wendover the salt lies flat and hard and dry — the best surface for automobile racing ever discovered. The crystalline salt body that makes the famous Bonneville Lats Race Track covers an area of 200 square miles.
–This location is the site of recent land speed records set by wheel-driven and jet propelled vehicles. This card likely dates from the 1960s.