I've been using my own prior knowledge, the internet, and most of all Google street view history to compile these formerly mounted sirens of Minnesota into a map. Sirens which I am not personally sure of are labeled as such in their description, as my goal is to make this map as informative as possible. It is not complete, but the MSP metro area has all of the sirens I could add.
[https://www.google.com/maps/d/edit?mid= ... sp=sharing]
If you have any historical MN siren locations that are not on this map, please respond so I can add them to the list. I will be continuing to work on this map from time to time, checking town by town to see if I can spot sirens on street view.