The grizzly appeared to be very greatly astonished at this sudden invasion of man into his hitherto undisputed realm of rocks, and a little offended. With a deep bass-drum-like "huff, huff," he reared his huge body up on his hind legs, and, turning his wicked little eyes on them, uttered a deep warning growl, as much as to say: "Now, if you men will turn right around and go back, I will not harm you." "Shall we shoot?" asked Thure, cocking his rifle. "No, not if the brute will get out of our way," answered Rex. "We have no time to fool with grizzlies," and, cocking his own rifle, he started straight toward the grizzly. The growl of the bear deepened, and he made no sign of giving way to the intruders. "All right, old man," and Rex stopped and threw his rifle to his shoulder. "Stand ready to fire, if my bullet fails to bring him down," he warned, as his eye glanced swiftly along the rifle barrel. But Rex Holt was one of the best rifle shots in California, and knew exactly where to send his bullet in order to make it instantly fatal; and there was no need of a second shot, for almost at the instant of the crack of his rifle, the huge beast, with a deep startled, "huff," and a staggering leap toward them, tumbled sprawlingly to the ground, as if all his tough muscles had been suddenly turned to hot tallow, and with a few quiverings, the great frame lay still. "No time to bother with him now. Let him lay there for the present. Come on," and Rex, pausing by the side of the grizzly only long enough to assure himself that the monster was dead, hurried on up the canyon. For half an hour longer they struggled on over the broken rocks that covered the bottom of the canyon; and then they came to where the canyon made an abrupt turn, and, widening out a little, ran straight ahead for half a mile or more. The moment they made this turn and looked up the clear stretch of canyon, all uttered a shout of triumph. Some two hundred yards from them and near the east wall of the canyon grew a huge oak tree; and, perhaps a hundred yards farther up the canyon, stood a tall pillar of white rock. "The Big Tree!" yelled Thure exultingly, starting on the run for the tree. "Lot's Wife!" shouted Bud, racing along after Thure. Rex and Dill and Dickson hastened after the excited boys; and, in a few minutes, all stood beneath the giant branches of the great oak. The tree was some seventy-five feet high and nearly as broad as it was high; and its huge trunk grew so close to the wall of the canyon that the ends of its great limbs on that side had been pressed tight up against the rocks. "Well, we are here at last!" Thure's face was flushed and his eyes were sparkling with excitement. "Now, for the hidden entrance to Crooked Arm Gulch!" and his eyes turned eagerly to the walls of the canyon.