Messer/Mayer Mill is a three and one-half story, front-gabled grist mill on a raised fieldstone foundation and sheathed with narrow clapboard siding. Its interior retains original milling equipment dating from 1873 to the early 20th century, much of it supplied by the Edward P. Allis Company of Milwaukee. The first floor contains millstones and roller mills, the second floor holds flour sifting, bolting, and grain storage bins, the third floor has George T. Smith middling purifiers used to produce high-grade white “Alaska Patent Flour,” and the basement contains machines and equipment associated with the Oliver Evans grain elevator system and the James Leffel and Company turbine. The mill contributed to the early industrial and commercial growth of the Town of Richfield at Pleasant Hill, produced flour into the 1930s, and was the town’s only grist mill between 1879 and 1925. Its cattle feed grinding business operated from the late 1890s until 1954, and the property also includes an intact 19th century homestead and several outbuildings built by the Messer and Mayer families.