Charles B. Keller studied printmaking with Bertha Jaques and B.].O. Nordfeldt. He won an honorable mention for his aquatints at the 1915 Panama Pacific Exposition in San Francisco.
In 1909 he traveled through Europe - England, France, Germany and especially Spain where he spent time in Ronda, traveling and recording the mountains and towns of the region. In this etching Keeler uses the contrast of bright light and deep shadows to give emphasis to the remotness of the fortified city. The artist has pencil inscribed this impression with a Whistler-like "butterfly" after the title.
The ancient Andelusian city of Ronda is located in the Malaga province in Southern Spain, and is divided by the El Tajo Gorge, through which the Guadalevin River runs. The Puente Nuevo bridge, which spans the divide, began construction in 1759 and took 34 years to build. Ronda is noted for the development of modern bullfighting.