Appleton Milo Harmon (May 29, 1820 – February 27, 1877) was an early member of The Church of Jesus Christ of Latter-day Saints and a leading pioneer of the emigration to Salt Lake City and the settlement of Utah Territory. Harmon was born in Conneaut Pennsylvania, the son of Jesse Pierce Harmon and Annie Barnes, he married Elmeda Stringham in 1846. He was devoted to his religion and was an industrious and multitalented builder who constructed sawmills, a cotton gin, pony express roads, furniture, wagons, and worked as blacksmith and other trades. He is often remembered for building an early version of the modern odometer, using the design of William Clayton and Orson Pratt. This "Roadometer" was built in 1847 during the trek of Brigham Young's vanguard company, and it improved the efficiency of logging the daily mileage, information that was vital to subsequent travelers of the Mormon trail. Harmon kept a detailed journal of his trek west and his mission to England that has been published.