When Oleta Eleanor Mittelstadt was born on 20 March 1898, in Rost, Jackson, Minnesota, United States, her father, Robert G. Mittelstadt, was 30 and her mother, Berta Auguste Schulz, was 25. She had at least 4 sons and 1 daughter with John Ahrend Post. She lived in Jackson, Minnesota, United States in 1898 and Ewington Township, Jackson, Minnesota, United States for about 40 years. She died on 3 August 1986, in Sioux Falls, Minnehaha, South Dakota, United States, at the age of 88, and was buried in Rost, Jackson, Minnesota, United States.