"They are," Rob said slowly. Resting on his shovel, he gazed up at the point where the buttes divided to form a deep coulee.

The leaders of the flock had come rather slowly over the crest of the hill, but now the whole herd came pouring down the glen. The thousand or more animals bleated crazily as they smelled the water and the deep, rich grass below them. Two sheep dogs maneuvered them with short, sharp yelps, glancing back for directions to the sheep herder who stood above and with his hat signaled to them what to do.

Walking toward the glen, Rob motioned to the sheep herder to come down. At first the man paid no attention, but when Rob had whistled sharply two or three times, he slowly began to descend the hill.

"He doesn't want to hear me," Rob said. "You'll see. He'll pretend he doesn't understand. Those Mexes are a coony lot; pretend to be stupid, but are sharp as nails when it comes to hanging on to a good grazing ground."

Watching the sheep flow along, Rob and Harry waited. After a while the herder came down the glen toward them.

"Say, he's not a Mex at all!" Rob exclaimed. "He's an American! It must be that herder of Joyce's."

The herder, who was a good-looking, heavily built fellow about twenty years old, stopped and looked at Rob without speaking. His felt hat was drawn forward over his eyes. He carried a heavy stick that was thick and knotted at the end.

"How do!" he said, glancing inquiringly from brother to sister.

"I suppose you know that this land has been filed on?" Rob began. "I'll have to ask you not to herd your sheep in 'round here."