The original millstone came from the Harriman Mill, begun by Dr. William P. Harriman south of Pilot Grove at Mt. Vernon in the late 1860's. It was constructed by Anthony Johnston, a millwright and stone mason from Kentucky who built several other mills in Cooper County. Laura Williams came to Missouri from Kentucky with the Harrimans, and one of her many duties was leading the horses to turn the sweeps in a never ending circle. The flour produced there was known as "White Rise Flour." In 1918, under the ownership of Albert Adair, the operation was converted to steam power and called the Pilot Grove Roller Mill. Phillip Mueller and Sons hauled logs for firewood from the Clear Creek area. The average annual output was 15,000 bushels wheat, 162,000 pounds cornmeal, and 3,000 bushels of other grain. The mill and its spring-fed pond were dismantled in 1935.