OK, I'll put you out of your misery!
Notice that shiny steel ball on the ground? They are there to test the firmness of the salt lake - most likely for a forthcoming X-15 flight. Shiny ball was dropped from a certain height and depression measured. F-104s were often used to conduct touch and goes on lakebeds as well. There was a infamous event once when Armstrong went up with Yeager in a 104B for such a test. Well, they ended up getting the 104b bogged in a lake - opps! Yeager made a big hooplah about this in his book. Ah, but Yeager, Armstrong flew the X-15 and walked on the moon!