found the sources of the large streams that empty themselves into the Pacific and Atlantic oceans. The Black Hills and the table lands, called Prairie Hills, which separate the sources of the upper Missouri from those of the Mississippi, the Ozark and the Masserne ridges may all be considered as so many collateral chains of the Rocky Mountains.
According to trigonometrical calculations and observations made by means of the barometer, Mr. Bonneville, in his memoirs, asserts that the summits of some of these mountains are 25,000 feet high.' This height would appear much exaggerated if we consulted only the testimony of the eyes, but it is well known that the mountains which are found in immense plains are not unlike ships seen on the ocean; they appear much less elevated than they are in reality. Whatever may be the height of these colossal mountains, it was at their base that we hoped to meet our dear neophytes. But a messenger -we had sent to acquaint them with our arrival has just returned and informed us that the Indians who lay encamped there about a fortnight ago went in a southerly direction to hunt the buffalo. We know not whether those Indians were Flatheads or belong to another nation, and it is to obtain information on this subject that we are going to dispatch a second messenger. In the meantime I shall continue my journal. The numerous notes which, on account of our slow progress, we have been enabled to take on the spot will warrant that exactness of description which is the more desirable, as it is a quality frequently wanting in the accounts given of these distant regions. Not to exceed the bounds of a lengthy letter, I shall say but little concerning perspectives, flowers, birds, animals, Indians and adventures.
With the exception of the ridges which run parallel to
2 Bonneville's " calculations " and " observations " were all practically worthless from a scientific point of view.
As elsewhere stated the highest of the northern mountains is less than i4,ooo feet high.