"Look it!" pointed Jesse. "She starts below Forty, at St. Louis, and goes north almost to Forty-nine, and then she drops down again to Forty-five at the Three Forks. And Lewis had observations on latitude and longitude right along. Wonder what he thought!" "He did a great deal of thinking," said Rob. "He had the conviction that so great a river must run deep into the Rockies--he insisted on that. Then he had the Indians at Mandan to give him some local maps. And he had Sacagawea, worth more than them all for local advice in a tight place where no one else had been ahead. It's wonderful, if you study it, to see how he made all those things work together, and how he used his brains and his reason all the way across. Even about his pet portable boat, he didn't sit down and cry. He did the next thing." "And proceeded on!" "And proceeded on, yes." "Well," concluded Jesse, "even if my eagle and my island are gone, I suppose I'll have to admit that this place is the real portage. They saw the Rockies right along now. They threw those canoes into the high, too!" "Tracking and poling, pretty soon now, and a fine daily average," nodded Rob. "And now I don't suppose that we need just feel that we've funked anything by not sticking to our boat all the time, and taking a pack train here; because Clark or Lewis, or both of them, and a good many of the men, walked a lot of the time from here, hunting and scouting and figuring on ahead." "That's so!" said Jesse. "Where were their horses all the time?" "None above the Mandans," said Rob; "maybe not that far. They started with two, and picked up one, and one died--that's the record up to the Sioux. But beyond the Mandans they hoofed it, or poled and paddled and pulled. They couldn't sail the canoes--they gave that up. And now both their perogues were left behind. So when they left the old eagle on his broken tree, and the savage white bears all along here, and the rattlesnakes and everything else that tried to stop them here, they drew their belts in and threw her in the high--that's right, Jess." "And speaking of the portage," he continued, "Uncle Dick told me to get a wagon and follow down as close as we could to our camp and get our stuff all up to a place above the White Bear Islands, and go into camp there until he came in with Billy Williams and the pack horses, from his ranch on the Gallatin, near the Forks. So that's a day's work, even with a flivver--which I think we'll use part way. Time we set out and proceeded on, fellows." They turned away from the Great Falls of the ancient river, in part with a feeling of sadness. Jesse waved his hand toward the Black Eagle Falls. "The only thing is----" said he. The others knew Jesse was wishing for the wild days back again. CHAPTER XX READY FOR THE RIVER HEAD