On the evening of the 8th we encamped on one of these fresh-water lakes, which the traveler considers himself fortunate to find; and the next day, in latitude, by observation, 42° 20' 06", halted to noon immediately at the foot of the southern side of the range which walls in the Sweet Water valley, on the head of a small tributary to that river.
Continuing in the afternoon our course down the stream, which here cuts directly through the ridge, forming a very practicable pass, we entered the valley; and, after a march of about nine miles, encamped on our familiar river, endeared to us by the acquaintance of the previous expedition--the night having already closed in with a cold rain-storm. Our camp was about twenty miles above the Devil's gate, which we had been able to see in coming down the plain; and, in the course of the night, the clouds broke away around Jupiter for a short time; during which we obtained an emersion of the first satellite, the result of which agreed very nearly with the chronometer, giving for the mean longitude 107° 50' 07"; elevation above the sea 6,040 feet; and distance from St. Vrain's fort, by the road we had Just traveled, 315 miles.
Here passes the road to Oregon; and the broad smooth highway, where the numerous heavy wagons of the emigrants had entirely beaten and crushed the artemisia, was a happy exchange to our poor animals, for the sharp rocks and tough shrubs among which they had been toiling so long; and we moved up the valley rapidly and pleasantly. With very little deviation from our route of the preceding year, we continued up the valley; and on the evening of the 12th encamped on the Sweet Water, at a point where the road turns off to cross to the plains of Green river. The increased coolness of the weather indicated that we had attained a greater elevation, which the barometer here placed at 7,220 feet; and during the night water froze in the lodge.
