George McCarthy / Two stalagmites, Carlsbad Caverns, New Mexico, USA

George McCarthy / Flora of Big Bend National Park showing the distant "Mule Ears Mountains", Texas, USA

George McCarthy / View from rim of Grand Canyon, with sedimentary layers obvious, Arizona, USA

George McCarthy / Geothermal formations, Travertine terraces, Mammoth Springs, Yellowstone National Park, Montana, USA