One of the first casualties of modernization was the highly successful flour mill that S. F. Lathrop and had bought and rebuilt on the river in 1857. It continued even after Mr. Lathrop’s passing in 1896. In 1910 it had been the longest running business enterprise in Steamboat Rocks history. Fifty-three years of operation came to an end when the mill burned on November 2, 1910. The decision was made not to rebuild for a couple of reasons. Wheat was no longer a major crop in Iowa due to blight and insect problems,
coupled with the fact that many modern steam and later electric powered mills were springing up in the now more productive wheat growing areas.
Some of the last millers at Steamboat Rock’s mill included Paul Penelerick, Tom Gearhardt, and John Bass.