The road here leaves the river, which bends considerably to the east; and in the afternoon we resumed our westerly course, passing over a somewhat high and broken country; and about sunset, after a day's travel of 26 miles, reached Black's fork of the Green river--a shallow stream, with a somewhat sluggish current, about 120 feet wide, timbered principally with willow, and here and there an occasional large tree. At three in the morning I obtained an observation of an emersion of the first satellite of Jupiter, with other observations. The heavy wagons have so completely pulverized the soil, that clouds of fine light dust are raised by the slightest wind, making the road sometimes very disagreeable.
17th.--Leaving our encampment at six in the morning, we traveled along the bottom, which is about two miles wide, bordered by low hills, in which the strata contained handsome and very distinct vegetable fossils. In a gully a short distance farther up the river, and underlying these, was exposed a stratum of an impure or argillaceous limestone. Crossing on the way Black's fork, where it is one foot deep and forty wide, with clear water and a pebbly bed, in nine miles we reached Ham's fork, a tributary to the former stream, having now about sixty feet breadth, and a few inches depth of water. It is wooded with thickets of red willow, and in the bottom is a tolerably strong growth of grass. The road here makes a traverse of twelve miles across a bend of the river. Passing in the way some remarkable hills, two or three hundred feet high, with frequent and nearly vertical escarpments of a green stone, consisting of an argillaceous carbonate of lime, alternating with strata of an iron-brown limestone, and worked into picturesque forms by wind and rain, at two in the afternoon we reached the river again, having made to-day 21 miles. Since crossing the great dividing ridge of the Rocky mountains, plants have been very few in variety, the country being covered principally with artemisia.
18th.--We passed on the road, this morning, the grave of one of the emigrants, being the second we had seen since falling into their trail; and halted to noon on the river, a short distance above.