 So how long has mining been going on in our area? Well, a former Alton Township supervisor and local historian says it's thought mining along the bluffs and other nearby areas actually began more than 150 years ago before the city was platted. There were also a number of smaller mines scattered around the city. Don Huber tells the Big Z there's been mining in the area of the current limestone quarry for decades, but believes most of the underground activity is in areas other than directly under the park. I think it's the 17th.