Re: the above image. I'm not seeing what you're seeing there.
Here is some info from my Dad who is a private pilot re: this situation...
"The plane burns about 9 gals per hour and carries a total of 36 gallons. The typical cruise speed would be about 130 MPH so that gives you a radius of 620 miles around the airport! The mission for his flight was to go check out places for a possible land speed record attempt so he would be flying toward large flat areas. I don't know if he was trying to go towards Bonneville salt flats or what."