A major theme of Underground Ranger is that the Guadalupe caves and surrounding Chihuahuan Desert are linked not only by the creative actions of water and other natural processes, but by nature's inexhaustible desire to create a world of astonishing beauty. Throughout my years at Carlsbad Caverns, I never tired of exploring and learning about the desert.

My hikes along the Guadalupe Escarpment introduced me to a host of desert creatures, from the Mexican free-tailed bats that swarmed out of the entrance to Carlsbad Cavern on summer evenings to the mule deer that liked to graze near the park housing area and raccoons that seemed to appear just for the sake of being noticed. In the Guadalupe Mountains, I even confronted an angry rattlesnake in the dark and stared into the eyes of a charging mountain lion. (You can learn about Guadalupe Mountains National Park at www.nps.gov/gumo.)

It didn't take long to realize that the desert is a dangerously imperfect place. The seemingly impregnable limestone of the Guadalupe Escarpment is slowly crumbling and eroding away, while the open desert is a vast and trackless waste where distances invariably prove to be much longer than they appear; virtually every plant bristles with painfully sharp thorns or prickly leaves; springs are rare and often unreliable, even in the rainy season; and the summer heat is all but unbearable.

Many park visitors didn't realize that hiking into the desert without understanding its challenges or being adequately prepared to meet them could be dangerous at best and perhaps even fatal. That's why I always emphasized the four basic rules of desert travel when talking with hikers:

• Carry plenty of water with you—at least one gallon per person, per day.
• Wear a hat and clothing that will protect you from the sun. 
• Recognize your own limitations and never exceed them. 
• Never underestimate the harshness of desert conditions. 

Occasionally, a lack of understanding resulted in tragedy. Underground Ranger tells how I took part in a desert search-and-rescue operation and how a series of unfortunate mistakes led to a park visitor's death.

My adventures in the Chihuahuan Desert taught me that life and beauty often flourish under the most extreme conditions and that austerity and hardship have their place in the natural scheme of things.