On my daily visit to the range I found some textbook Fairy Ring. FR is a soil fungus that either kills grass or causes grass to grow in dark green circles because of a soil fungi that releases nutrients. Mushrooms are a symptom of this fungus as well. It is not a disease that causes much concern, especially on the driving range body. Fairy Ring is well understood by turfgrass pathologists but in the past, conspiracy theorists believed UFO's landing created the circles. I personally will go with the UFO's on this one.
