was seen the first magpie. On our return, we saw one at the mouth of the
Platte river. We left here one of our horses, which was unable to proceed
farther. A few miles from the encampment we left the river, which makes a
bend to the south, and traversing an undulating country, consisting of a
grayish micaceous sandstone and fine-grained conglomerates, struck it
again, and encamped after a journey of twenty-five miles. Astronomical
observations placed us in latitude 42 deg. 32' 30", and longitude 108 deg. 30'
13".

5th.--The morning was dark, with a driving rain, and disagreeably cold. We
continued our route as usual and the weather became so bad, that we were
glad to avail ourselves of the shelter offered by a small island, about
ten miles above our last encampment, which was covered with a dense growth
of willows. There was fine grass for our animals, and the timber afforded
us comfortable protection and good fires. In the afternoon, the sun broke
through the clouds for a short time, and the barometer at 5 P.M. was
23.713, the thermometer 60 deg., with the wind strong from the northwest. We
availed ourselves of the fine weather to make excursions in the
neighborhood. The river, at this place, is bordered by hills of the valley
formation. They are of moderate height; one of the highest peaks on the
right bank being, according to the barometer, one hundred and eighty feet
above the river. On the left bank they are higher. They consist of a fine
white clayey sandstone, a white calcareous sandstone, and coarse sandstone
or pudding-stone.

6th.--It continued steadily raining all day; but, notwithstanding, we left
our encampment in the afternoon. Our animals had been much refreshed by
their repose, and an abundance of rich, soft grass, which had been much
improved by the rains. In about three miles, we reached the entrance of a
_kanyon_, where the Sweet Water issues upon the more open valley we