"Must be," said Slim. "The rustlers never drove th' cattle in away around there. They sent 'em in from this end. Th' trail ends right here, an' it's here where th' rustlers drove th' cattle in."
"But where?" asked Bud. "There isn't a sign of an opening!"
"Because they closed it after them," went on the foreman. "I begin to see it now. There must have been a break in the wall of the old crater right about here. They drove th' cattle in an' it was an easy matter t' let some of th' dirt slide down an' fill it up again. Let's take a look with a view t' seein' if I'm right." It is easier to find a clue when you know just what you are looking for. And it did not take long for the experienced eyes of the cow punchers to discover where earth and shale from above had been recently dislodged and allowed to slide down to cover what must have been the same sort of natural opening into the side of the wall as that at the far end, closed by a fence of trees. This was to keep the cattle in without men being needed to ride herd.
"Yes, it does look as if they'd taken 'em in here," said Bud, when it was found that the trail of the steers led to the foot of the crater wall, where all signs stopped. "If we had looked up a little, instead of sticking so close to the ground, we might have seen this clue before."
"All in good time," observed Slim. "The question is, now, how can we get in there?"
"It will be easy enough," suggested Nort. "All you'll have to do will be to enlarge the crack we looked through."
"That's all right for us getting inside that crater," observed
Dick, "but what about our horses? They can't scramble up there."
"Then what can we do?" asked Bud. "Ride around to the other entrance?"
"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.