The picture was taken at the summit of Pike's Peak, Colorado, at an event to celebrate the 50th anniversary of the first ascent by an automobile.
On 12 August 1901 a Locomobile steamer driven by C.A. Yont and W.B. Felker became the first car to reach the summit, at 4,300 metres above sea level.
The puzzle photo was taken on 17 August 1951. The passenger in the Locomobile is identified as Mrs Yont, though I don't know what her relationship was to the original driver.
An annual hill climb competition has been held at Pike's Peak since 1916, making it one of the oldest motorsport events in the US.