Kerkhoven, Minnesota: Singing Highway

There is a peculiar stretch of road Just west of the town of Kerkhoven, MN on Highway 12 about half way between Kerkhoven, MN, and Pennock MN. There seems to have been a road surface test area there many many years ago. If you travel over this area the "tire sound" you hear in your car changes pitch five times and sounds as though it is singing. My wife is from the area. We always listen for the singing as we travel to and from willmar MN. [Brad Graber, 08/18/2002]