You sit back in your saddle—all saddles in these parts have cruppers and breastplates to prevent your sliding over the animal’s ears as you go down or slipping off behind as you go up a mountain path—and as you watch the tossing line of packs below, the speculation forces itself as to the consequences of a mule’s misstep. That it is not all idle speculation is shown by the scattered skeletons below in the valley, bleached to varying degrees of dull white.

We do not descend to the pavement of river-washed stones on the bed of the valley. Twenty yards above, the trail leads abruptly off to the left into a narrow ditch worn in the face of the cliff, which in places has been scooped out to allow for the width of the packs, leaving an insecure overhang of rock above.

For miles we followed the contour of the valley, clinging to the steep slopes and the sides of the cliffs that hedged it in. Then down a clayey bank the trail started diagonally across the bottom of the valley to the farther side. Occasionally we would come suddenly on a little clearing where two or three Indians, grisly through the ashen grime, were burning charcoal—little twigs scarcely bigger than one’s finger. We came out at the farther side of the valley against the cliffs of the mesa beyond. On the little stony flat before them, three straggling huts of woven cane with thatched roofs of barley straw marked a lonely hacienda. A few dirty Indians and their slatternly wives lounged about. A short distance beyond, the trail led over the steep talus at the base of the cliffs; then on up through a narrow, wedge-shaped crevice that wound back and forth in short ascending turns, till it disappeared over the edge of the mesa a thousand feet above. For miles on either side it was the only break in the cliff; and as we looked at the stiff prospect ahead of us, the rocky descent of a few hours before seemed like gentle morning exercise in the park.

For a short distance the trail ran straight up over the loose shale; then the real ascent began. Ten yards to the right, then ten to the left, and steeper with each change. The mules humped their backs and scratched along on the toe of the hoof, choosing their foothold with the nice precision of a cat crossing a sprinkled street. Two turns to the right, then two to the left; then a rest of half a minute, when without urging they would recommence the ascent. Slowly and tediously we climbed, and finally rode out on a broad, level plateau that stretched away and merged with the desert hills of the distance. Below us toiled our pack-train, tediously weaving back and forth on the zigzag trail. As each section reached the level ground, the arriero dismounted and went among his animals, talking mule-talk and easing loads to a better balance or tightening the stretched cinches. All the unkempt, hairy sides were heaving with heavy breaths. A few lay down—a bad sign in a pack-animal. But in twenty minutes every mule was apparently as fresh as ever, wandering about and foraging on the stiff, wiry bunch-grass of the arid soil. And when we started they stepped off easily under their loads, with their long ears briskly flapping. The two small arrieros left us here and returned to Quilca, for the chief difficulties were passed, and the rest was but persistent plodding over the desert to San José.

The trail over the plateau had been worn in parallel furrows like the thin strip of a newly ploughed field. Each mule chose his furrow and insistently walked there, resenting the effort of any of the others to get in ahead of him. When a collision occurred you could hear the rattle of nail-kegs and the clatter of shovels, picks, and hardware a half-mile off as they butted and shoved for the right of way. Our two remaining arrieros rode in the rear, muffled in their gaudy woolen ponchos. Occasionally a lean arm would shoot out from under its folds and the knotted thong bite the flank of some lagging mule. These mule-drivers’ thongs are long, braided strips of rawhide spliced into the curb-rein—they use no snaffle—ending in a heavy knot. Its twelve or fourteen feet lie coiled in the bridle-hand until called into service. Then with a twist of the wrist, it feeds rapidly out through the right hand, humming like a sawmill as it circles round his head, and landing with a thwack that generally corrects the indisposition for which it is intended. Often the arrieros imitate its vicious hum, and it will frequently prove sufficient.

The trail was distinct enough—there was no fear of wandering away from it—a slender ditch worn in the bed of the arroyo. Here and there a ragged little hole dug in the soft walls of white rock marked the lonely home of some desert badger; and again we would ride past whole colonies of them. In these badger villages the holes fairly honeycombed the sides of the trail and the bluff walls of the arroyos, and the shuffling claw-marks of the badger trails scarred the dust in all directions. There were no other signs of life; not even the scaly windings of a lizard were to be seen, and the sparse patches of bunch-grass had long since disappeared.

Mile after mile we pushed up these narrow valleys. The badger-holes disappeared, and strange desert growths began to appear from time to time. As we had ascended, the clouds had seemed to lower, and now we could see on either hand the light mists floating about us.

One more steep loomed ahead. We pushed through the damp strata of mists clinging to its sides, and came out on the flat land above in the long level rays of the setting sun. Below us, over the clouds, it cast its cold, blue shadows and sparkling high lights, transforming those shifting, unstable vapors into rippling waves of golden foam. To the east the whole desert glowed with color. The long furrows of the trail wove themselves in patterns of orange and purple. Rolling shadows, rich in their changing violets, faded slowly and softly away to the left. Gorgeous reds and scarlets, madders, oranges, crimsons—every brilliant color of the palette—spread in glowing masses, changing with each minute of the dying day. The saddle-stiffness, cracked lips, and parched throat, dry with the alkaline dust, were forgotten—even the dismal clank of the bell-mare slowly toiling in the lead mellowed to a far-off chime—and in those few brief moments of the vanishing day we felt the subtle desert spell.

The shadows grew colder and merged one into another; the desert dimmed, a few stars glistened, and, as though a door had closed behind us, we passed into the night. Twilight is short in the tropics. Down by the horizon on our right the Southern Cross slowly lighted up—four straggling points of light that feebly struggled with the blazing stars about them. We closed in behind the swaying shadow of the mules, from which came the subdued rattle of packs and creaking cinches, that were the only sounds to disturb the dark stillness. It was but a little way now; in another hour we would be in camp.

Out of the shadow ahead came the clash of picks and shovels, the rattle of a load as it struck the sand, and the swaying shades of the mules divided around a black mass stretched on the trail. It was the first note of exhaustion. For twelve hours the mules had plodded at the same steady gait, rested only by the halt on the cliff, miles back, and the wonder of it was that, with their loads, none had dropped before. As we rode up we could see against the faint starlit ground the sprawling silhouette of the beast, lying as he fell, the long, expressive ears limp on the desert sand. The arrieros dismounted and pried him on his feet again, and patiently he hit the trail. In the next half-hour four more went down. At one time half our mules were down, and we strung out over the desert for two miles picking them up.