They were off like darts, swerving from the direction the boys came, stretching out to reach the swell of the nearest hillock. “Come on!” yelled Chet, and pounded Hero in the flank with his heels. The horses seemed to enter into the spirit of the chase. They thundered up the rise at the heels of the elks. Dig wanted to shoot at once; but Chet begged him not to. “You’ll be shooting right into the air as we go up hill!” he shouted. “You’ll shoot clean over their heads, Dig.” “I don’t want to lose my chance as I did with those buffaloes,” returned Dig, much worried. “Wait till we’re over the rise. Then we can shoot down on them—” But Chet was mistaken. The elks flew over the rise. It would have been a long shot had they tried it then. On rushed the bay and the black, both as eager in the chase as their young masters. Chet fairly rose in his stirrups to see over the round top of the mound. He saw the tossing horns of the bigger elk; and then—he saw something else! “Dig! Dig! they’re here!” he gasped, and almost fell out of his saddle, he was so amazed. CHAPTER XXIII—THE FIRST BUFFALO Chet was taller than his chum and he had risen in his stirrups, while Dig lay out on the black’s neck and cheered him on. So the first named lad saw over the rise and out upon the plain. The two elks were hammering down the slope, their slender legs doubling under their round bodies, and stretching out again with almost bewildering swiftness—like the driving-rods of fast-turning engines. But they were a good shot, if not an easy one, for the boys were not directly behind them. A ball, directed properly, would have raked either beast from forward of the hip into, and through, the heart. This was not to be, however, Chet and Dig were destined never to knock over those elks. What arrested Chet’s hand was the sight of a herd of animals grazing on the plain, and almost as close to him as the elks. The sight of them brought the cry to his lips: “Dig! Dig! they’re here!” “Who are here? Those rascals?” Dig yelled, thinking first of the thieves who had robbed them the night before. But the next moment he saw the grazing herd-_the sixteen buffaloes_! “After them! Quick!” shrieked Dig, and spurred his black. He almost seemed to lift Poke off his feet when he struck the tiny spurs into him. Poke shot ahead of the bay and Dig rose in his stirrups. He was not as good a shot as Chet; but he could not miss that brown body which was squarely in front of him. It was not the big bull Dig aimed at; that animal, in fact, he did not see. But the creature in line with his rifle barrel was big enough. It was a well grown bull, and when it raised its head and swung the huge bulk of it to see the charging boys, it looked formidable. The chums were tearing down upon the buffaloes, losing sight of the elks entirely. The nobler game made them ignore the other.