This shot comes from a book titled "Sports Car Races In Southern California", by Art Evans.
Perhaps the most significant event held at Pomona was the 1959 Examiner Grand Prix. Leading the start was Jerry Unser driving a Curtis-Cadillac, who was just ahead of #69 Dan Gurney in a 4.5 Ferrari. Next was Max Balchowski in # 70 Ole' Yeller I, Carroll Shelby (98) in a Maserati 5.7, Chuck Daigh (6) in a Kurtis 500, Billy Krause (53) in a a 4.5 Maserati, George Amick (181) driving a Porter/Mercedes-Chevy Special, Jim Jeffords (141) in a Scarab, Wayne Weiler (82) behind the wheel of a Lister-Corvette, Sam Weiss in #55 Porsche RSK in 10th place, and just entering into the shadow of the bridge was #50, Ken Miles in a Porsche RS Spyder in 11th place.
In spite of a large field of heavy iron and big bore engines with star drivers, Ken Miles won this event going away in the Spyder, followed by the other small litre Porsche of Weiss. At one point in the Pomona Raceway history, Ken Miles held the track record in the RS Porsche for quite some time. (This ought to make Cranky's day!)
The Pomona course was 2 miles long with only seven wide sweeping turns, and a front straight of over 5/8 mile, which is now part of the drag strip used at the Pomona Fairplex for the NHRA Winternationals and the Finals each year.