"'The mountains do not appear very high in any direction tho' the tops of some of them are partially covered with snow, this convinces me that we have ascended to a great hight since we have entered the rocky Mountains, yet the ascent has been so gradual along the vallies that it was scarcely perceptable by land. I do not believe that the world can furnish an example of a river runing to the extent which the Missouri and Jefferson's rivers do through such a mountainous country and at the same time so navigable as they are. if the Columbia furnishes us such another example, a communication across the continent by water will be practicable and safe.' "Class dismissed. I see Billy has got the horses." The boys put away their maps and rolled their beds. All of the party being good packers, it was not long before they had left their camp ground on the knoll and were off upstream once more, edging the willow flats and swinging to the ford of the Madison, which they made with no great danger at that stage of the water. Thence they headed back for the Jefferson fork, having by now got a good look at the great valleys of the Three Forks. "Which way, sir?" asked Billy now of their leader. "Shall we stop at the real headquarters camp of the Three Forks, just about a mile up--where the Indian girl told them she had been taken prisoner when she was a child?" "Too near town!" sung out Jesse, who overheard the question. "Let's shake the railroad." "She's right hard to shake, up in here," rejoined Billy. "Off to the right is the N.P., heading for Butte, up the Pipestone. We couldn't shake the left-hand branch of her this side of Twin Bridges, and that's above the Beaverhead Rock. From there upstream to Dillon, along the Beaverhead River, there isn't any railroad. We can swing wide, except where she canyons up on us, and may be get away from the whistles. Only, if we go as far as Dillon, we hit the O.S.L. She runs south, down the Red Rock, which is the real Missouri River. And she runs up the Big Hole, which the _Journal_ calls the Wisdom River. And there's a railroad up Philosophy Creek, too----" "And up all the cardinal virtues!" exclaimed Uncle Dick. "I don't blame the boys for getting peeved. Now, we don't care for canyon scenery so much, nor for willow flats with no beaver in them. I would like the boys to see the Beaverhead Rock and get a general notion of how many of these confusing little creeks there were that had to be worked out.