“Well, boys, we sure do seem to be in for a run of hard luck,” remarked Bart Witherbee as he climbed out of the auto with the others, and they ruefully surveyed the obstruction. It was a big sugar pine and lay entirely across the road. To go round it was out of the question, for the ground on each side was timber grown and rocky.

“There’s only one thing to do—cut it away,” pronounced Bart Witherbee, starting back for the tonneau to get the axes.

“No; I’ve got a better scheme than that,” said Billy suddenly, and then broke out with a loud: “Look here, fellows!”

He pointed excitedly to the trunk of the tree where it had been severed from the roots.

The fresh marks of an axe were upon it.

“It’s Luther Barr and his crowd,” cried the boy. “They figured on blocking us, and they would have succeeded but for a scheme I’ve just thought of.”

“What’s that?” demanded Bart Witherbee.

“Why, let’s get the rope out of the tonneau and haul the tree out of the way with the auto.”

“Say, that’s a good plan,” assented Bart Witherbee, starting back for the auto once more. In a few minutes he had the rope and it was quickly looped round the tree and then tied to the rear axle of the auto, after the machine had been turned round.

Billy took his place at the wheel and started the car up. There was a great sound of cracking and straining, and for a second the auto’s wheels spun uselessly around. Then suddenly as the boy applied more power the great log started.

Amid a cheer from the boys it was pulled entirely away, and a few seconds later the road was clear.

“Well, what do you think of men who would descend to a mean trick like that,” demanded Bill angrily as the adventurers resumed the road.

“As it happened it didn’t do them much good,” remarked Bart.

“I should say not,” rejoined Billy. “I reckon they didn’t think that we could hit upon a way of getting it off our track.”

The auto chugged on through the sweet-smelling pine woods till the declining sun began to tint their dark branches with gold.

“Hadn’t we better send the boys a wireless?” asked Billy, and as the others agreed that it was important to know where they were the mast was set in position and a call sent out. A reply was soon obtained from the others, who were camped at a small plateau further up the side of the foothill.

Half an hour later the boys were all in camp together, and the events of the day were discussed with much interest. It was a wild country in which they found themselves. Great stretches of barrens mingled with dense pine woods, and Frank and Harry had serious thoughts of once more taking to the plains. Bart Witherbee, however, assured them that if they kept on to Calabazos they would find a good landing and ascending place, and from there could easily wing their way to level ground. He represented to them that they would be taking a short cut also by following this route. So the boys decided to keep on to Calabazos with the old miner, a decision which was not wholly disinterested, for they were anxious to see the mine of which he had told them so much.

Naturally, the position of the other contestants in the race was a topic that came up for a lot of discussion, but the boys were still talking it over when it was time to turn in without having arrived at any definite conclusion. From what they had heard in White Willow they were pretty certain that Slade’s aeroplane was disabled. Concerning the condition of the dirigible or her whereabouts, however, there was by no means the same amount of assurance.

They were chatting thus and speculating on their chance of winning the big prize when Bart Witherbee suddenly held up a warning hand.

“Hark!” he exclaimed. They all listened.

“Did you hear anything?” he asked of Frank.

“Not a thing,” replied the boy.

“I thought I heard footsteps up the trail,” returned the old miner, “but I guess I was mistaken.”

“Why, who could it be?” asked Billy.

“It might very easily be some of Luther Barr’s gang prowling about. We are near the mine now, and they are no doubt determined to get the papers showing its location before I have a chance to file my claim,” put in Bart Witherbee.

The boys kept a sharp lookout after this, but they heard no more, if, indeed, there had been any sound, which they began to doubt, and soon after they were snug asleep in their blankets.

Suddenly Frank was awakened by shots and loud shouts. Springing up from his blankets he was amazed to see Bart Witherbee rolling over and over on the ground with somebody who seemed of immense size gripping him tightly.

The boy could hear Bart gasping for breath. He seemed as if he were being crushed.

Frank’s shouts awakened the others.

“Robbers!” cried Billy.

“Indians!” yelled Harry.

“Murderers!” cried old Mr. Joyce, as their sleepy eyes took in the struggle.

Harry raised his rifle to fire at Bart’s antagonist, whoever he might be, and was about to pull the trigger, even at the risk of hitting the miner, when Frank interrupted him with a cry of:

“Don’t shoot, you might hit Bart.”

“But the robber will kill him.”

“It’s not a robber at all,” suddenly cried Frank, as the two contestants rolled over nearer to the firelight. “It’s a big bear!”

“Give me a knife—quick!” gasped Bart, as he and the bear rolled about. Hastily Frank threw toward him a big hunting weapon. One of the hunter’s arms was free, and he reached out and grabbed the weapon. With a rapid thrust he drove it into the bear’s eye. With a howl of pain the animal raised its paws to caress its injury. At the same instant Frank’s rifle cracked and the animal rolled over, seemingly dead.

“Are you hurt?” asked the boys, rushing forward to Bart.

“No, I don’t think so,” cautiously replied the miner, feeling his ribs. “I feel as if that thar critter had caved me in, though.”

An examination soon showed that Bart was uninjured and the bear quite dead.

“That was a close call,” remarked the miner, wiping his knife. “I guess that must have been what I heard prowling around here early in the evening, although that dead brute there was no more dangerous than that old sharp, Luther Barr.”

“Did you think it was some of his gang attacking you?” asked Billy.

“I sure did,” replied the miner. “I was lying nice and quietly asleep when all of a sudden I felt something nosing me, and could feel its warm breath on the back of my neck. If I had not been so sleepy, I’d have known it was a b’ar by the strong smell of its fur, but as it was, I thought it was Hank Higgins or Noggy Wilkes. I soon found out my mistake, though.”

After this interruption the boys turned in and slept quite soundly till daybreak, when they were up and the journey to Calabazos resumed, after the bear had been skinned and the steaks enjoyed. Before the start was made Bart gave the boys full instructions for landing the Golden Eagle in Calabazos, which lay across a small canyon not very many miles ahead.

The road now began to dip down hill, and the auto rattled along at a lively clip. Here and there the boys noticed small huts, and tunnels drilled in the hillside, which the miner told them were abandoned claims.

“Some of them is worked yet by Chinamen,” he explained: “but when the poor yellow men do unexpectedly make a strike there’s always some mean cuss ready to come along and take it all away from them. I think the gov’ment ought ter do something about it.

“Half a mile ahead now is the bridge across the canyon, and then we’ve only got a short distance to go before we’re in Calabazos. My mine is about ten miles from there,” he said a few minutes later. “I wonder who is sheriff there now. You see, that makes a whole lot of difference when yer are filing a claim against a rival. You’ve got to have the sheriff on your side, for he can make a lot of trouble for you in getting to the gov’ment office, where first come, first served is the rule.”

“But you have your claim staked, have you not?” asked Billy.

“Sure; but that don’t bind it till you’ve registered your claim,” rejoined the miner. “You see, mine’s an abandoned claim, too. Old fellow name of Fogg had it once. At least I found his name cut on a tree.”

And now they came to a sharp turn in the road.

“The bridge is right around the corner,” said the miner, “you had better put on your brakes, Billy, or we may have a runaway, for there’s a terrible steep bit of hill runs right down to it.”

The boy obeyed, and it was well he did so, for while they were speeding toward the bridge, a rude affair of pine trunks laid across long stringers suspended high in the air above a pine-clad canyon, there was a sudden shout from Bart Witherbee, who was acting as lookout.

“Hold up, boy! Stop the car!” he shouted.

“What’s up?” asked Billy, shutting down his emergency brakes with a snap in obedience to the miner’s urgent tone.

“Look there!” The miner pointed ahead.

At first the boys could see nothing the matter with the bridge, but a second glance showed them that something very serious indeed had occurred to it.

Somebody had removed two of the trunks that formed a roadway, and right in the centre of the structure was a gaping hole. Had the auto come upon it unexpectedly it must have gone through into the depths of the canyon beneath.

They all got out of the auto, all, that is, but Mr. Joyce, who was busy figuring on an invention, and hastened down to the bridge. The planks, there was no doubt, had been deliberately removed by some one, and that those persons were Luther Barr and his party none in the party could for a moment doubt.

Suddenly the bell of the wireless on board the auto began to ring.

“The boys are sending us a message,” exclaimed Billy.

He and Lathrop raced back up the hill to the car, where the latter placed the detector over his ears and tapped out his “ready” signal.

The others watched him eagerly. It was not a minute before they saw that something serious was the matter. The boy’s face paled, and he seemed much concerned.

“What is the matter?” anxiously asked Bart Witherbee. “Air the boys in trouble?”

“The worst kind of trouble, I am afraid,” breathed Lathrop in a tone of deep concern. “They are in the hands of Luther Barr.”

“Where?”

“On the other side of the canyon.”