The Richards Grist Mill, originally known as the Rock Grist Mill, was owned and operated by S. W. Richards & Co. Designed and built by Utah millwright Frederick Kesler at the direction of LDS Church President Brigham Young, with James Leithead and Reuben Broadbent as foremen, this tall stone mill replaced Farmington's first grist mill, which Dr. Willard Richards had built nearby in 1852. Dr. Richards had also opened a saw mill in 1851 four miles up North Cottonwood (Farmington) Canyon, and after the Utah Territory legislature granted him the right to build a toll road to it, that mill produced timber for local homes and lumber for a shingle mill at the mouth of the canyon. When Dr. Richards died in 1854 at age 49, his nephews Franklin D. and Samuel W. Richards gained ownership of the mills and replaced the pioneer gristmill with this larger structure. Construction began in 1857 using local stone and lumber and some of the original hand-hewn timbers from the first mill, and when it was finally finished, Franklin D. Richards wrote in his diary on June 19, 1862, that it was ready to start milling. Although two other mills were built in Farmington, the Old Rock Mill supplied the community with meal and flour for more than forty years. After 1906 it was converted into one of Farmington's first power stations, and it was later used as an ice house, for fruit storage for a local store, and as the Heidelberg restaurant in 1960.