The clay hole and chimney shown on the mural are reminders of a once successful brickmaking venture. When clay deposits were discovered, Dr. D.C. Dunham organized the first brickyard in 1881, known as the Anoka Pressed Brick and Terra Cotta Company. It was located at the site of the present clay hole swimming area. The digging of clay from this source was terminated when diggers hit a spring at about 90 feet. The clay hole has remained utilized up to the present time by several generations of swimmers.