Harmon Petefish was the son of George (Johann Georg) Petefish (1790-1868) and his first wife Mary Aughe (abt 1798-1823). He was born in Warren County, OH, then moved with his family to Morgan County, Illinois in 1830. Harmon married both his first wives (probably sisters) in Morgan County. He first married Elmira Taylor on Nov. 28, 1844, who bore him one son, David Franklin. She died on Nov. 15, 1847. On Oct. 11, 1848 Harmon married Susannah Taylor in neighboring Cass County, who gave him four children. She passed away eight days after the birth of her daughter Cordelia, in September of 1857.

By this time, Harmon had moved from Illinois to Jasper Co. Iowa, the move having come sometime between 1854 and 1857. He settled near the little town of Clyde (no longer extant), where he became a pillar of the local church. He was known to preach from time to time, and, after Susannah's death, having five children at home without a mother, he was introduced to his third wife by a fellow member of the Clyde church. Mary Catherine Conner became Harmon's wife on May 22, 1859, bringing her daughter Alice to the family. Mary went on to give him six children, and outlived him by seven years.

In later years Harmon sold his farm land at Clyde and moved to Polk County, perhaps near the ghost town of Ivy. He worked on Ezra Plummer's farm, and raised and sold meat in the Des Moines area. He was active as a Mason. By his three wives Harmon had eleven children.

He died on Aug. 9, 1883 from injuries sustained in a tragic train accident. After a visit and dinner at his daughter Mary Jane Williamson's home, Harmon and his daughter Sarah Catherine (Kate) headed off toward home in their buggy. At a train crossing they waited for a passing train, then after it cleared they immediately drove the buggy into the path of another train they had not seen or heard because of the dense grove of trees at that spot. Kate was caught up on the locomotive's cow catcher, unconscious and with a broken collar bone. She survived. Harmon was thrown from the crushed buggy, and suffered severe injuries. He and Kate were carried onto another train headed into Des Moines, and were conveyed from the East Side depot back to Mary Jane's home on E. Locust and 17th. Harmon was placed tenderly on a bed at his daughter's home and passed away within two hours of being brought there.