Thornton Quarry, in Thornton, Illinois, has an ever-growing waiting list of hopefuls awaiting a chance to descend to the lower rings of limestone tunnels and mining operations for the expansive ...

Below the quarry's floor is a layer of naturally ... "We think it's the largest dam in Illinois," Brown said. Once it comes online, Thornton Reservior will have the capacity to hold nearly 8 ...

The reservoir in the quarry will hold almost 9 billion gallons of water. After it fills, floodwaters will be slowly pumped out, treated, and sent to nearby waterways. It will be fully operational ...