"That would take too long," answered the foreman. "I fancy that Del Pinzo and his gang are on their way to this natural corral now, t' drive out th' cattle they stole from us. We've got t' get ahead of 'em!" "But how?" Bud wanted to know. "I think we can dig out enough of th' shale an' dirt they slid int' th' opening, so that we can get th' horses through," Slim answered. "We ought t' have shovels, but we can use sticks t' dig with. It will take longer, but it's the best we can do." Little time was lost in putting this plan into operation. With a hatchet, which formed part of their camp equipment, some strong poles were cut from one of the few trees that grew on the slope of the gorge, and with these digging operations began. It was slow work, but many hands were engaged and soon an opening was made so that entrance could be had to the original crack in the rocky side of the bowl. For it was by this crack that the cattle had been driven in. And the crack had only been partly filled with broken rock and earth to conceal it from view. "Yes, they did come in this way!" cried Bud as he and the others urged their horses through the opening and into the bowl proper--the crater of the extinct volcano. "Look, plenty of signs!" There was no doubt of it. The rustlers had driven the cattle into the defile, hazed them along until they reached the opening into this great natural hiding place, and then the rest was easy. The animals had been run into this solitary place, passing through the narrow, fissure-like opening in the rocky wall, a crack similar to, but larger, than the opening through which Bud had made his discovery. Then shale and dirt had been started, in a miniature avalanche, down the side of the slope, effectually hiding the means by which the cattle were secreted away. "No wonder we thought an airship had been used," commented Dick. Before them lay the vast crater of the old volcano, inactive for centuries. Nature had covered the hard lava with a layer of soil in which grew rich grass. And nature had further made the place an ideal corral for cattle by supplying a large spring of water. It was a "rustler's paradise," to quote Slim Degnan. As the boy ranchers rode into the amphitheatre, the cattle at the far end, and in the middle, stopped grazing to look at them. "We're friends of yours!" called Bud, waving his hat in the joy at finding his lost stock. "Yes, but here come some fellows who aren't!" shouted Yellin' Kid. "Where?" asked Bud, quickly. "There!" Kid pointed to the far end of the crater, if one may use the word "end" in referring to a circular bowl. The cowboy posse saw, riding at top speed into the great depression, a crowd of men, who, as they came nearer, could be recognized as the Del Pinzo gang. The Greaser leader was not in evidence, however. "They're after the cattle!" cried Nort. "Well, they won't get 'em without a fight!" shouted Bud.