A shallow sea advances and retreats several times during this period, leaving behind the layers named Kaibab Limestone, Toroweap Formation, and Hermit Shale. The Coconino Sandstone layer was ...

Two layers of stone underlie Mammoth's hilly woodlands. A sandstone and shale cap, as thick as 50 feet in places, acts as an umbrella over limestone ridges. The umbrella leaks at places called ...

This catastrophe appeared to be due to a combination of mining and late spring weather conditions. Here's what happened ...