Saturday, September 17, evening.--Gillette, Moore and Williamson left us this morning about 9 o'clock on their final quest for Mr. Everts, and the rest of our party soon resumed our journey. We have traveled about twelve miles to-day, about one-half of the distance being through open timber, and the other half over prostrate pines unmarked by any trail, and through which we found it difficult to make our way, although the obstructions were not so formidable as those on the south shore of Yellowstone lake.[X] About noon we crossed a high ridge which we had reached by a steep ascent, and on descending the opposite side we saw upon our left a large lake which Lieutenant Doane and some others of our party think is at the head of Firehole river, and they suggested that we make our way to this lake and take as a guide to the Firehole the stream which they believe will be found flowing from it. They argued that by so doing we would be relieved from all uncertainty concerning the course to be pursued in order to reach the Firehole river; but they were easily persuaded that if the Firehole does take its rise in that lake, we can as certainly strike that river by pursuing our present westwardly direction as if we followed the plan suggested by them. Hauser and I feel sure that this large lake is the head of Snake river. In the afternoon we passed another ridge and descended into a small open valley where we found a spring of good water, and where we are now camped, near a very small creek, which runs in a direction a little north of west, and which I believe flows to the Firehole or the Madison river. Our direction of travel to-day has been governed somewhat by our compasses, but we have neglected to make allowance for the variation of the magnetic needle, which I think is about twenty degrees east of the true meridian. Therefore in trying to follow a westerly course, we have in reality taken a course about twenty degrees north of west. As we passed the large lake on our left to-day, I observed that there was no ridge of land between us and the lake; therefore I believe that it is in the Snake river valley, and that we have to-day twice crossed the main range of the Rocky Mountains. The fact that the Snake river valley is so readily accessible from Yellowstone lake, gives me hope to-night that Mr. Everts may have made his way out of the forest to some settlement in the Snake river valley. There is still four or five inches of snow on the ground, but there is plenty of long grass under it, and our horses are faring tolerably well, and will soon fill themselves with either grass or snow. There is no clear space large enough for us to pitch our tent. We have had our supper--an indifferent and scanty meal--and each man is now seeking with varied success a dry spot beneath the sheltering branches of the pines whereon to spread his blankets.