I gaze deep into Mexico from my lookout in the Chisos Mountains, a forested plateau Edward Abbey considered "an emerald isle in a red sea." Two thousand feet below me, the Mule Ears—twin volcanic formations, which from here look like Doberman ears—thrust from the plains. Far to my left stands the Sierra del Carmen, a rocky bulwark blotted by haze.

There is nothing funnier than the human animal." -- Walt Disney

The Chisos are a place for raptors and rapture, and if I could, I'd dive off the escarpment and soar to the Rio Grande.

Dizzy with too much open space, I shoulder my pack and duck back into the trees, descending on the resin-scented Pinnacles Trail. I reach a meadow of wheat-colored grass, where an oak tree catches my eye. Acorns patter from its canopy. Then, the tree's crown jiggles violently—more acorn hail. I approach the tree for closer inspection, but before I get there, two black balls bounce toward me, furry and droll. They come to rest 10 yards from my boot tips. Bear cubs. The ranger had told me about mountain lions, but I had forgotten about desert bears.

Where is Mom?

The tree stops shaking. Seconds later, with a hoarse huff, their mother rushes down the trunk and rumbles between her cubs and me. There's no curiosity in her demeanor, only fierce, no-nonsense maternity. Raising my hands in appeasement, I slowly back off without breaking eye contact. Her ears—initially flattened against her skull—perk up. Her posture relaxes, so I keep on removing myself, taking care not to trip. By the look on her face, this seems acceptable. More intent on foraging than on confrontation, she herds her cubs into a thicket. With the last black rump gone, and my pulse back to normal, I chuckle, enchanted by this showdown in the Texas mountains, where bears drop from trees.