ut at the Peace River
Landing, beyond Little Slave Lake. That's where we came out when we
crossed the Rockies, down the Finlay and the Parsnip and the Peace.
I've got that course of ours all marked in red."

"But we go the other way," began Jesse, bending over his shoulder and
looking at the map now. "Here's the mouth of the Peace River, more
than four hundred miles north of here, in Athabasca Lake. Both these
two rivers, you might say, come together there. But look what a long
river it is if you call the Athabasca and the Mackenzie the same! And
look at the big lakes up there that we have read about. The Mackenzie
takes you right into that country."

"The Mackenzie! One of the very greatest rivers of the world," said
Rob. "I've always wanted to see it some time. And now we shall.

"I'd have liked to have been along with old Sir Alexander Mackenzie,
the old trader who first explored it," he added, thoughtfully.

"I forget just what time that was," said Jesse, hesitating and
scratching his head.

"It was in seventeen eighty-nine," said Rob, always accurate. "He was
only a young Scotchman then, and they didn't call him Sir Alexander at
all until a good while later--after he had made some of his great
discoveries. He put up the first post on Lake Athabasca--right here
where our river discharges--and he went from there to the mouth of the
Mackenzie River and back all in one season."

"How did they travel?" demanded John. "They must have had nothing
better than canoes."

"Nothing else," nodded Rob, "for they could have had nothing else.
They just had birch-bark canoes, too, not as good as white men take
into that country now. There were only six white men in the party,
with a few Indians. They left Athabasca Lake--here it is on the
map--on June third, and they got to the mouth of the great river in
forty days. That certainly must have been traveling pretty fast! It
was more than fifteen hundred miles--almost sixteen hundred. But they
got back to Athabasca Lake in one hundred and two days, covering over
three thousand miles down-stream and up-stream. Well, we've all
traveled enough in these strong rivers to know how hard it is to go
back up-stream, whether with the tracking-line or the paddle or the
sail. They did it."

"And now we're here to see what it was that they did," said Jesse,
looking with some respect at the ragged line on the map which marked
the strong course of the Mackenzie River toward the Arctic Sea.