But the boy, arrived at the point where he must strike off for the party, realized that the time for delay was over, and turning to the station agent, who had been eyeing him curiously, he asked for information about the government surveyors. There was no difficulty in finding out roughly the direction in which the party had traveled, but the description of the route over the apparently interminable cactus plains somewhat perturbed Roger, accustomed though he now felt himself to be to find his way over the faintest trails. But he was a boy, just the same, and the cacti looked forbidding and menacing, and the lad wished profoundly that the old frontiersman, who had been his companion on the first ride to Death Valley, were with him now. But there was no help for it, he had to join his party no matter what the trail was like or whither it led. His next question, implying the desire to buy a good mule and the ability to pay for it, aroused considerably more interest, and the station agent so bestirred himself in the matter that Roger felt sure he had a commission in view. It was but a short time before three mules were brought for his inspection, all sound beasts so far as the boy could judge, and he counted himself fortunate to strike an agreement with the owner of the mule, whereby, for a little extra payment, one of the herders should accompany him on the trail to the Survey camp. The ride was long and dry, and the boy was amazed to learn from his companion that a few years before these arid plains had been a grazing country. "Where has all the grass gone?" he queried. "Señor," replied the Mexican, "it was thisa way. Alla the grass has been eaten. There wasa too moocha the cattle on the land, they eata the grass moocha too short, and the grass cannot maka the seed." "But," objected Roger, "aren't the roots still there?" The herder shook his head. "No, Señor," he answered, with a sweeping gesture; "if the grass get moocha short, the rain not soaka in but runa right away, the ground all same as dust, and wind blowa the earth away from the roots and alla dry up." "I see," said Roger thoughtfully. "Then putting too much cattle on land is like cutting the forests on the mountains too heavily. Deforest the mountains and the water floods the streams and is wasted, crop the plains and they become a desert. I see." The distance to the Survey camp was not great, being but little over twenty miles, but the country was not conducive to rapid traveling, and as the boy allowed his companion to set the pace it was almost evening when they arrived. The party had just come in from the day's work, and Roger immediately presented his letter to Mr. Barrs, by whom he was warmly welcomed.