Sure enough, the camp was awakened at an early hour the next day by a couple of rifle shots, and an excited commotion among the Indians. The boys in whom, as in all healthy American youths, the hunting instinct was strong, at once scrambled from under their blankets, seized their rifles and dashed through the bushes toward the small stream which flowed from the mountains toward an arm of Prince William Sound.

A dozen rods from the camp, they came upon the guide and the Indians standing around a large bull caribou whose head boasted a magnificent pair of antlers. The animal’s throat had been cut and the Indians had already set to work to take off the hide.

“Got him the first shot,” said the guide, “and tried to get another, but they was too swift fer me. They was six in the herd. However, this is enough, and the poor things is bein’ killed off fast enough fer their hides and horns without our takin’ more’n we need.”

“Why didn’t you call us?” asked Jack, “I should like to have got a shot at some big game before we leave Alaska.”

“Fer that very reason,” replied the guide, “it’s the close season now, and we can only kill what we need for meat. Besides that, it’s ticklish business gettin’ a shot at caribou, and two persons would have made more noise than one, and I wanted very much to get one or two fer these Indians, who need it, as I told you. Hurry up there, you Siwash, and get yer meat and have yer feast fer we’ve got to be movin’.”

“What a handsome pair of antlers,” said Rand, who was something of a naturalist.

“Best head I ever see,” said the guide. “I’d be glad to make ye a present of it if there was any chance of yer gettin’ it out of Alaska at this season. However, we’ll take it back to Seward and maybe Colonel Snow can find some way to do it.”

By this time two of the Indians had cut the carcass up, while the others had built a hot fire. Several steaks were cut off and roasted before the flames under the guide’s direction for the boys’ breakfast, and they found the meat juicy and palatable. Then the Indians turned to and had their “feast.” They partially roasted the flesh in great chunks, and for an hour gorged themselves like starving men just escaped from the desert.

“T-t-hey won’t be able to walk,” commented Pepper, after gazing at the gastronomic feat that put any of his previous efforts in the shade.

“Let ’em alone fer that,” said the guide, “I never in my life see anything that could carry a bigger cargo of grub, and do a day’s work than a Siwash. I s’pose it’s because starvation’s got ter be a regeler perfession with ’em. They can lay in food like a camel does water, and then go fer days without it.”

The Indians, having packed some of the meat for the next day, cut the rest into thin strips, and with the caribou’s head, hung them to the branches of trees out of reach of bears, to be called for on their return. The riding horses were also turned loose, in a broad meadow to stay until the return, and nothing but the pack animals taken.

Their morning journey carried them higher and higher into the foothills of the Kenai range, and the trail became more rugged. About nine o’clock the Indians began to show some eagerness and excitement, and the chief told the guide that they would soon sight the peaks. Finally, the Siwashes ran ahead to the top of a sharp rise and excitedly beckoned. The boys joined them, and as they reached the summit of the ridge a peculiar scene met their gaze.

The other side of the ridge sloped sharply for nearly two hundred feet to a valley nearly half a mile wide, paved with gravel and boulders, and as bald of vegetation as a desert. The rocks on the slope of the ridge and along the sides of this wide shallow ravine were cut as sharply and worn as smooth as if the stone cutter’s chisel had shaped their surfaces.

A quarter of a mile distant, and almost in the middle of the valley stood an immense obelisk of rock some three hundred feet high, dividing, some distance from the top into three sharp pinnacles. On the surface of the middle spire could be seen a small black dot. The Indians were dancing with excitement, and the boys themselves felt a thrill as they realized that they were nearing the climax of a great mystery.

“That looks like a great river bed, in which the water had dried up,” remarked Rand, “I never saw anything like it before.”

“Bed of an old glacier,” said the guide, who had come up. “Lots of ’em in this country.”

“That explains it, then,” said Jack, excitedly.

“Explains what?” inquired Dick.

“How they got up there,” replied Jack. “Don’t you see? This valley was full of ice once nearly to the tops of those rocks, and when it came down and melted off, the bodies of the mammoths dropped out, and the natives gathered the tusks and stored them in the cave which they could easily reach with the glacier so near the top. Then the snow gave out somewhere in the mountains and the glacier gradually pushed its way out and melted, leaving the cave high and dry.”

“All right for you, Jack,” said Gerald. “Begorra, you’ve had that story already written, I see. But it looks like the real goods.”

“I’ve read of these things before,” replied Jack.

“That’s about what happened,” commented the guide. “Some geological sharps who were up here last year explained one of these rocky holes the same way.”

The pack horses were now brought up to the top of the ridge and unloaded, as they could not very easily be taken down the valley slope. With the greatest care the plane was removed from the two pack animals, and with ropes lowered on its own wheels down the gravelly slope. The motor and other machinery was slid down upon skids cut from the forest and placed along the bank. At the bottom, the Scouts set to work putting the machine together.

“Ah,” said the guide, with the air of a great discoverer, “I see what yer scheme is now. Ye’re goin’ up in that arrerplane, and see if ye can git a peek in that hole up there.”

“Better than that,” replied Gerald. “We’re going to get up and get into that hole.”

Delighted at finding they were nearing the goal of their hopes with so few obstacles, the Scouts worked cheerfully and earnestly upon the reassembling of the plane, and by noon had replaced the motor and tested every stay, brace and control. Then, after a dinner of caribou meat and coffee, they wheeled the plane over the gravel to the foot of the great gray granite obelisk. As they neared it they could see that the dot at the summit took more and more the shape of the ace of clubs, the mouth of the cave appearing as if cut by the hand of an artist, into gothic form. The Indians were awe-stricken spectators, scarcely able to raise a hand to work, so impressed were they with the preparations.

Some seven hundred feet of strong, but light manila rope had been attached to the lower frame of the machine, and to guard against accidents as much more had been coiled under the seat. It was Gerald’s intention to rise over the obelisk, and trail the rope over the rock between two of the pinnacles, thus affording means for the raising eventually of a block and tackle and a rope ladder by which they would be able to reach the summit. But the “best laid plans o’ mice and men” and even Boy Scouts, “gang agley,” as Burns says.

They found a patch of smooth gravel, clear enough of boulders to allow the aviator to make an excellent start, and after trying out the engine to find that it was working without a flaw, Gerald got a fine running start and mounted into the air. Working west half a mile, mounting all the time to raise his trailing rope from the ground, he turned and circled around the mighty mass of rock looking for the most likely point on the top over which to trail his line. As he passed he caught a glimpse of the interior of the cave, and saw that it was much larger than it looked from the ground to be.

Turning again, he concluded to pass between two of the pinnacles, and immediately volplane down on the other side. As he approached the rock he shut off the engine, and the aeroplane began to slow down. The propellor stopped, and the plane sank perceptibly. One plane struck the side of a pinnacle and crumpled up, the weight of the engine carried the middle section, and the machine sank down a wrecked mass of canvas and wires upon a narrow plateau between two of the points. Gerald was scarcely jarred from his seat by the impact and soon freed himself from the wreckage to find himself marooned upon the top of a perpendicular rock three hundred feet from the ground. The Scouts and the Indians set up a cry of dismay when the possibility of the disaster became apparent, but as soon as he had freed himself, Gerald assured them of his safety, and of the fact that he had plenty of room to stand and move around upon. Another thing that relieved their fears was that he had about sixteen hundred feet of rope available. He first gave his attention to the cave, and found that by an easy climb of seven feet he could reach the mouth. He found the hole to be about ten feet deep, by as many broad. It was perfectly lighted and piled in the rear was what appeared to be an indiscriminate mass of bones buried under a pile of dust. Dragging some of them out, he saw that the pile consisted of some ten fine mammoth tusks, well preserved, two of which were still attached to part of the skull of the animal, a fine museum relic. The rest was made up of a miscellaneous collection of ivory—narwhal’s horns and tusks of the walrus—all weighing about five hundred pounds.

There were also many Indian relics, nearly all in a decayed condition. He soon notified his companions of what the cave contained, and asked them to send up the block and tackle on the rope he had dragged over the pinnacle. Fastening the block by a turn of the rope around a small point of rock above his head, he bundled up the bones in canvas cut from one of the planes and lowered it to his comrades. When the last of the ivory had been lowered, together with the Indian relics which he thought the Siwashes might prize, he took the other rope from the aeroplane and knotted it at ten foot intervals. This he fastened to another point of rock and threw down. Then he placed a noose of the tackle rope around his body under his arms. Yelling to his companions to lower away he bent a last sorrowful look upon his beloved aeroplane, and with tears in his eyes, swung off with his knotted rope in his hands. Placing his feet against the perpendicular rock, he swung out by his knotted guide line, and fairly walked down the face of the obelisk backward.

The loss of the machine and Gerald’s stupendous adventure and escape was almost too much for the emotions of the Boy Scouts, and with watering eyes they surrounded their comrade with many a hug and pat upon the back.

As for the Indians, they were on their knees almost worshipping the mammoth’s tusks and the Indian relics. To hide their emotions the boys began at once preparations for departure. The ivory was divided up, and under the guide’s direction taken across the gravel and up the ridge, where it was packed upon the horses. The remainder of the stuff was abandoned, including the ropes, gasoline and tools to keep the derelict and exalted plane company. When they reached the top of the ridge, and were about to descend into the foothills, the Scouts turned, and with bared heads paid a last tribute to the “First Airship in Alaska.”