The bottom collapsed with the mine underneath, making it very deep. Don't Edit. Mark Torregrossa ... At 250 feet deep, Torch Lake is Michigan's deepest inland lake by 75 feet.

There’s an abundant reserve of potash deep underneath portions of Michigan’s Lower Peninsula, worth $65 billion to Michigan’s economy, according to the man who wants to mine the mineral, a ...

According to "Michigan Gold: Mining in the Upper Peninsula" by author Daniel Fountain, ... Aquila's operation would include an 700-foot deep, 83-acre open pit mine, about five miles of roads, ...

About a mile-and-a-half underground in north-central Michigan, an almost-forgotten reserve of the potassium-rich mineral salt potash could be worth $65 billion to the Michigan economy.

In December, Michigan Potash obtained the last of the permits it needs to begin construction. The company would use solution mining to free the potash from the deep earth, valued at $65 billion. That ...

Michigan Potash would use a process known as solution mining, which would pump heated water and brine (concentrated salt water) into a deep geologic formation known as the A1 Evaporite.

Michigan Potash & Salt Co. LLC announced on Tuesday that it entered into an offtake agreement to sell 650,000 short tons of the macronutrient used in fertilizers annually to a Chicago-based Archer ...