Once more they pushed through heavy undergrowth close to the river, traveled up a rather lofty bank, and found themselves in flatter country, beyond which at some distance rose some mountains.

“I’ll bet you,” said Rob, “that this is just about where Mackenzie climbed the tree to look around—you can’t see much from the river down there, and his men were complaining about the hard work, and he didn’t know where he was. So he climbed a tree to have a look.”

“Well, Mr. Rob,” said Alex, “if you don’t mind, I’ll let you do the climbing, while I sit here and smoke. I’m not quite as light as I once was.”

“All right,” said Rob. And, divesting himself of his cartridge-belt and jacket, a little later he began to make his way up to the topmost branches of the tall spruce, breaking off the dead limbs as he slowly advanced upward.

Rob remained aloft for some moments, but at last descended and rejoined Alex.

“Now, what did you see, Mr. Rob?” inquired the old hunter.

“Well, I don’t know,” said Rob; “it’s hard to figure out exactly, of course. But Mackenzie talks about high mountains off to the northwest, and a parallel range of mountains running to the south, with a narrow valley between. That, of course, must be this river, and as near as I can tell, it must have been about here that he and Mackay and the Indian hunters took to the shore to spy out the way.”

“And jolly well got lost, too, eh?”

“They certainly did—got lost from their boat for an entire day! I can imagine how they felt when they didn’t know whether the boat was above them or below them. Mackenzie says the mosquitoes about ate them up. They sent branches down the river to let the boatmen know they were above them. It wasn’t until night that finally they found the boat was far below them. I’ll warrant they were glad when they got together again. The truth is, the men were almost ready to turn back and leave Mackenzie where he was.”