As the hours wore on, the mountains, from mere wavy outlines of blue, began to take on definite form. They now showed formidable, seamed and rugged. As well as the boys could perceive at that distance, the hills were covered with dark trees to their summits and intersected by dense masses of shadow, marking cañons and abysses. A more forbidding-looking range could hardly be imagined, yet in the foothills to the southeast there grew great savannas of succulent bunch grass on which several ranges of cattle roamed. The noon camp was made in the foothills near a small depression in which grew some scanty grass of a dried-up, melancholy hue. The wagon road was at some little distance from this, and as soon as a halt was made, Jose, at Harry's orders, took a shovel from the wagon and started for the dip in the foothills. "Going to dig potatoes?" asked Tubby casually, as he watched the lazy Mexican saunter off. "No, water," responded Harry. His serious tone precluded any possibility that he was joking. But the idea of water in that sterile land seemed so ridiculous to the boys that they burst into a laugh. "I mean it," declared Harry. "Here, you fellows, take those buckets from under the wagon. We carry them to water the mules. Pack them over to that dip and in half an hour you'll be back with them full." "Huh! guess I could carry all the water that will come out of that place in one hand," commented the fat boy. "Don't be rash," laughed Harry; "before long you'll take digging for water as a matter of course." "Wish you could dig for ice-cream sodas," muttered the fat boy absently, picking up a bucket and starting off after Jose. Rob and Merritt followed, while Harry busied himself unhitching the mules for their noonday rest. This done, he lighted a fire of sage-brush roots, and awaited the return of the boys. The first thing the boys saw Jose do when he got to the bottom of the dip was to lie flat on his stomach and place an ear to the ground. "He's going to sleep again," suggested Merritt. "Looks like it," agreed Rob. But this time the Mexican did not drop off into a peaceful slumber. Instead, he presently straightened up, and shouldering his shovel, began tramping off once more. The boys followed him over several dips and rises till at last he descended into another depression in which grew some scanty herbage. Here he repeated the other performance and arose with a grunt of satisfaction. Suddenly he began digging furiously. "Wow! he's making the dirt fly," exclaimed Tubby, as the industrious Mexican dug as frantically as though his life depended on it. So fast did the work of excavation proceed that soon quite a large hole had been made in the soft ground. "Pity they haven't got him down at Panama," commented Merritt dryly. Jose had paid no attention to the boys hitherto, but now he suddenly shouted, pointing downward into the hole: "Mira qui!" "What's that about a key?" asked Tubby.