"Oh! we shall soon see him!" cried Roger, fixing his eyes on the spot, as near as he could calculate, whence that last reply had come. "Now, keep watching, both of you, while I signal to him again that the coast is clear." He added one more tremulous trill to his notes; to his astonishment the answer was so plain and clear that it seemed to come straight out of a pine tree not more than twenty-five yards away. "Why, he must be back of that tree, I think!" stammered Roger, uneasily, for he realized that Jasper Williams could never have gained such a Position without some of their eyes detecting his advance. Just then a bird flew out of the pine and alighted in another at some distance away in another quarter. Dick himself instantly gave the signal whistle, and there came an immediate answer; but it was now from the quarter whither the bird had flown. Roger gave a cry of disgust, while Dick laughed softly. "Good-by to Jasper this time, I'm afraid, Roger!" he said. "How mean that was for a silly little bird to have the same whistle Jasper had made up as his signal," said Roger, looking downcast. "Come, there's no use in our staying here any longer. If that bird keeps on whistling I might feel like using my gun to bring it down, for I'd think it was mocking me." "The poor thing thought a mate was calling," Dick assured him; "or else some other male bird that wanted to fight it. I warrant you, it is just as upset as you can be over the mistake." They pushed on once more, and inside of two hours had come upon at least seven more geysers, some of which were spouting, while others were quiet at the time the three pilgrims happened to find the craters. Now and then the boys would converse in low tones, for Dick knew that this was the best way to keep his companion's spirits from drooping. When other things failed, Dick could always interest him by referring to the wonderful luck that had befallen them, in giving them a chance to stay all winter at the Mandan village with the exploring expedition, so as to go on into the Golden West when spring came around. The uncertainty that lay ahead seemed to appeal to the spirit of adventure that lay deep down in the hearts of the young pioneers. "When we break camp in the spring and leave here," Dick went on, as though he had mapped it out in his mind, "we will have to head into the Northwest, Captain Lewis told me." "Why go that way instead of straight into the West, or turn toward the Southwest?" Roger asked him, just as Dick knew he would be likely to do. "It seems that the two captains have been picking up all the information they can from every source," Dick explained; "and this, when boiled down, causes them to believe there is a better opening over the great Rocky Mountain chain up there than in any other quarter. Besides, I believe they have an idea there is a great river that flows to the sea, the headwaters of which start in the land of the Blackfeet."