"Turning southward, a new and strange scene bursts upon the view. Filling the whole field of vision, and with its boundaries in the verge of the horizon, lies the great volcanic basin of the Yellowstone--nearly circular in form, from fifty to seventy-five miles in diameter; and with a general depression of about 2,000 feet below the summits of the great ranges which form its outer rim. Mount Washburn lies in the point of the circumference, northeast from the centre of the basin; far away in the southwest, the three great Tetons on Snake River fill another space in the circle; connecting these two highest are crescent ranges, one westward and south, past Gardiner's River and the Gallatin, bounding the lower Madison, thence to the Jefferson and by the Snake River range to the Tetons; another eastward and south, a continuous range by the head of Rose Bud, inclosing the sources of the Snake, and joining the Tetons beyond. Between the south and west points, this vast circle is broken through in many places for the passage of the rivers; but a single glance at the interior slopes of the ranges shows that a former complete connection existed, and that the great basin has been one vast crater of a now extinct volcano. The nature of the rocks, the steepness and outline of the interior walls, together with other peculiarities to be mentioned hereafter, render this conclusion a certainty. The lowest point in this great amphitheatre lies directly in front of us, and about eight miles distant: a grassy valley, branching between low ridges, running from the river toward the centre of the basin. A small stream rises in this valley, breaking through the ridges to the west in a deep cañon, and falling into the channel of the Yellowstone, which here bears in a northeast course, flowing in view as far as the confluence of the small stream, thence plunged into the Grand Cañon, and hidden from sight. No falls can be seen, but their location is readily detected by the sudden disappearance of the river; beyond this open valley the basin appears to be filled with a succession of low, converging ridges, heavily timbered, and all of about an equal altitude. "To the south appears a broad sheet of water--the Yellowstone Lake. Across the Grand Cañon, on the slope of the great mountain wall, is the steam jet seen this morning; and in the next ravine beyond it are six more of inferior volume. Still farther south are others, to the number of perhaps twenty, and to the southwest more of them, scattered over the vast expanse of the basin, rising from behind the wooded hills in every direction. The view in this respect strongly resembles that from the Alleghanies, where they overlook iron and coal districts, with all their furnaces in active operation, save that one looks in vain here for the thrifty towns, country villas, steamboats, and railroad depots."