1972-07-dd Doris Young by Everett's Dodge Charger. Alert viewer and cousin Dick Young observed the location to be the Eades bridge in St. Louis Missouri which spans the Mississippi river into Illinois.
Glen, the bridge in back of your Mom while standing by the tail of the Charger is the Eades Bridge in St. Louis. (See this link to confirm it...
When I first saw the one of her standing by a riverboat, my first intuition was, "St Louis, down on the Mississippi River dock", and I'm pretty sure that's accurate.