What lay beyond them, and between them and the Pacific, was not even guessed at.

The Rocky Mountains were not known to exist, so far as the territory newly acquired by the United States was concerned, although under the name of "Stonies" their northern extensions in British America were already down on some maps.
The National Government Undertakes the Work.
The West had passed beyond its first stage of uncontrolled individualism.

Neither exploring nor fighting was thenceforth to be the work only of the individual settlers.

The National Government was making its weight felt more and more in the West, because the West was itself becoming more and more an important integral portion of the Union.

The work of exploring these new lands fell, not to the wild hunters and trappers, such as those who had first explored Kentucky and Tennessee, but to officers of the United States army, leading parties of United States soldiers, in pursuance of the command of the Government or of its representatives.