In 1917 Marin painted some of the most abstract watercolors of his career, influenced in part by an exhibition that year of Georgia O’Keeffe’s watercolors of simplified natural forms. In this and related works, the artist developed a nontraditional technique: he manipulated charcoal with a rag, which he rubbed and wiped through a semidry charcoal wash. Painting a mixture of powdered charcoal and dilute black watercolor over pale washes, he wiped horizontal and circular marks to suggest rock formations. The charcoal particles in the wash clumped as the wash dried, leaving a gritty pattern as they settled into the valleys of the textured paper. Marin’s choice of a stepped frame enhances the dynamism of water washing across rocks.

— Exhibition label, John Marin's Watercolors: A Medium for Modernism, January 19-April 17, 2011, Galleries 124-127.