On the morning of June 3, 1805, camp was moved across the Missouri to the point on the south side of Maria's River. Before noon, Lewis wrote,
…Capt. C & myself stroled out to the top of the hights in the fork of these rivers from whence we had an extensive and most inchanting view; the country in every derection around us was one vast plain in which innumerable herds of Buffalow were seen attended by their shepperds the wolves; the solatary antelope which now had their young were distributed over it's face; some herds of Elk were also seen; the verdure perfectly cloathed the ground.
View from Decision Point, Marias River Mouth
This scene is a panorama from the high point to which the captains climbed on the morning of June 3,1805. It opens on a view down the Missouri River, which is flowing northward at this point. The Corps' campsite of June 2 is behind the trees to the right east of the river
Above those trees are the mountains seen faintly on the horizon, and tragic moment in history. Turning toward the northwest (your left), you are looking across an island and a side channel of the Missouri. The Marias River is out of sight behind the trees
Continuing to turn to your left, you will encounter a plant you might recognize, the yucca. But do you know its romantic story? Click on the hot-spot.
Another turn to your left beings the Missouri River back into view. A hot spot over the mountains on the horizon leads to an illustrated geography lesson.
The first aerial photographs were taken from balloons in the late 1850s, but the process of making maps based on them, called photo- grammetry, awaited the advent of the airplane after 1900. World Wars I and II, plus the accelera- tion of Western resource extraction in the interval between them, provided ample motivation.
Southward they thought they discerned two mountain ranges, one behind the other, and they figured the ranges' bearings—generally from southeast to northwest. They were almost right.
Actually there are three ranges in that direction. The nearest are the Highwood Mountains, roughly 35 miles distant. About 20 miles south of them are the Little Belt Mountains. Still farther south—and overlapping them, from Lewis and Clark's perspective—are the Big Belt Mountains, whose peaks reach up to 9,200 feet. The northwest end of the Big Belt range is intersected by the Missouri River, flowing between the cliffs that Lewis would, 46 days in the unforeseeable future, name the "gates of the rocky mountains."
The Belt Mountains
A conspicuous dark band of Cretaceous sandstone all the way around a prominent hill summoned the name Girdle Butte in the 1880s, which was soon recycled into Belt Butte, which in turn contributed the name to a town and a creek, and two mountain ranges. Geologists began in those mountains to study a huge wedge of Precambrian sedimentary rock that extends from western and west-central Montana through northern Idaho, which they called the Belt Formation.
It is difficult for most viewers today to separate the three ranges when seeing them from the explorers' point of view, much less to estimate their bearings or distances, without at least referring to an ordinary highway map. Yet despite the captains' misreading of the land we must admire their skill in interpreting the topography along their route, when the nearest they could come to an aerial perspective was from the highest point in the vicinity that they had the time to climb.
There are ninety different named mountain ranges in the present states of Montana and Idaho together, and from the linked sketch-map showing their relative locations one can imagine how hard it would be to tell one from another at ground level, even today. Some are well over a hundred miles long; others, such as the Moccasins, consist of just a couple of undistinguished buttes rising a little above the plain.