The only time I remember watching steam on the M&StL was as a small child as they were tearing up the rail north of Lake Mills. I believe it may have been a decapod with the work train also probably a steam crane and some flat cars. I was small, under ten years old I believe and we lived at least two maybe three miles from where the work was done. It was at the very end of the stretch north outside of Lake Mills.
As you take US 69 Northbound from Lake Mills IA you can still see much of the old abandoned roadbed sitting to the east of the highway.