we reached the mouth of Deer creek, where we encamped. Here was abundance
of rich grass, and our animals were compensated for past privations. This
stream was at this time twenty feet broad, and well timbered with
cottonwood of an uncommon size. It is the largest tributary of the Platte,
between the mouth of the Sweet Water and the Laramie. Our astronomical
observations gave for the mouth of the stream a longitude of 106 deg. 08' 24",
and latitude 42 deg. 52' 24".

27th.--Nothing worthy of mention occurred on this day; we traveled later
than usual, having spent some time searching for grass, crossing and
recrossing the river before we could find a sufficient quantity for our
animals. Towards dusk we encamped among some artemisia bushes, two and
three feet in height, where some scattered patches of short tough grass
afforded a scanty supply. In crossing, we had occasion to observe that the
river was frequently too deep to be forded, though we always succeeded in
finding a place where the water did not enter the carts. The stream
continued very clear, with two or three hundred feet breadth of water, and
the sandy bed and banks were frequently covered with large round pebbles.
We had traveled this day twenty-seven miles. The main chain of the Black
hills was here only about seven miles to the south, on the right bank of
the river, rising abruptly to the height of eight and twelve hundred feet.
Patches of green grass in the ravines on the steep sides marked the
presence of springs, and the summits were clad with pines.

28th.--In two miles from our encampment, we reached the place where the
regular road crosses the Platte. There was two hundred feet breadth of
water at this time in the bed, which has a variable width of eight to
fifteen hundred feet. The channels were generally three feet deep, and
there were large angular rocks on the bottom, which made the ford in some
places a little difficult. Even at its low stages, this river cannot be