Two of the most memorable examples of the Prairie school landscape architecture are situated in Iowa. One of these is the Rock Glen development in Mason City, designed by Walter Burley Griffin; the other is Eagle Point Park in Dubuque. Neither of these Iowa landscape designs is situated within a characteristic midwestern prairie landscape. Instead, both are placed within highly picturesque rocky glens; they have far more to do with the eighteenth-century English sense of the sublime than with the horizontality of the prairie.
The designer of Eagle Point Park with its “nature-aiding” park structures was the Chicago-trained landscape architect Alfred Caldwell. Caldwell was appointed park superintendent in 1933, and he devised a plan that he named “The City in a Garden.” With a large WPA crew funded through the federal government's relief programs of the depression years, Caldwell built his own version of Frank Lloyd Wright's Taliesin at Spring Green, Wisconsin. In lookouts, pavilions, shelters, stone circles, pools, and pathways he brought together the “organic” sensitivity of Wright in architecture and of Jens Jensen in landscape architecture. Native limestone was the fundamental building material, and he treated it so that the structures read as manmade, but at the same time their layered horizontality reflected the character of the nearby native limestone outcroppings. Just as William Steele and Purcell and Elmslie's Woodbury County Courthouse in Sioux City represents the high point of public architecture for the Prairie school, Caldwell's work at Eagle Point Park is a near-perfect summation of “organic” landscape architecture. A further indication of Caldwell's approach to the Prairie style can be seen in a house he designed for Ward F. Donovan. This two-story house (1941) is located in Dubuque at 1721 Plymouth Court. Within Eagle Point Park is