At the 2005 Bridges conference the author presented a paper titled, “Fairfield Porter’s Secret Geometry”. Porter (1907-1975), an important American painter, is known for his “naturalness” and seems to eschew any system of proportioning. This paper briefly traces other influences on Porter’s use of geometry in art and offers an analysis of two more of his paintings to reveal detailed and sophisticated geometric structures based on the Golden Ratio and Dynamic Symmetry.