This was a question put to me on a recent trip out with a buyer. Sure enough, the internet comes through again. While this data is from 2009, it is the most up to date and comprehensive I could find for railroad track activity in the Minneapolis/St. Paul area. Click here to view.
In Minnesota there are many railroad tracks that are inactive. Always check with the city to find out what the future plans are for the track. Most are being turned into bike and jogging paths. As a buyer you will want to know what the current and future use is and how that will affect your enjoyment of the property.