The glaciers did a real job on Iowa during their last surge. One of the benefits of the last ice age was the creation of conditions perfect for the production of rich, organic soil. That's what is abundant here close to the 42N line. This windmill near Rowley, Iowa is located in the middle of a farm field surrounded by the relative black earth in the foreground. It's one of the reasons that Iowa and other Midwestern states produce record number of corn and soybean crops annually. Know that.