Page:Popular Science Monthly Volume 7.djvu/403

Rh The agencies and conditions under which all of these features have been formed deserve mention, and in this and following chapters I shall briefly discuss this subject, in a manner as free from technical terms as will be consistent with accurate description.

The discussion will by no means be exhaustive, and I hope hereafter to treat this subject in a more thorough manner. In view of these facts, I shall not attempt any logical classification of the elements of the topography, nor of the agencies and conditions under which they were produced; but, commencing at the north, at the initial point of the exploration, I shall take them up in geographic order, as we proceed down the river.

—The area north of the Uinta Mountains embraced in the survey is but small Through the middle of it runs Green River, in a deep, narrow valley, the sides or walls of which sometimes approach so near to each other, and are so precipitous, as to form a canon.

The general surface of the country, on the north of this district, is about 1,000 feet above the river, with peaks, here and there, rising a few hundred feet higher; but south, toward the Uinta Mountains, this general surface, within a few miles of the river, gradually descends, and at the foot of the mountains we find a valley on either side, with a direction transverse to that of the course of Green River, and parallel to the mountain-range.

To the north, the water-ways are all deeply eroded; the permanent streams have flood-plains of greater or lesser extent, but the channels of the wet-weather streams, i. e., those which are dry during the greater part of the year, are narrow, and much broken by abrupt falls.

The rocks are the sediments of a dead lake, and are quite variable in lithologic characteristics. We find thinly-laminated shales, hard limestones, breaking with an angular fracture, crumbling Bad-Land rocks, and homogeneous, heavily-bedded sandstones.

The scenic features of the country are alike variable. On the cliffs about Green River City, towers and buttes are seen as you look from below, always regarded by the passing traveler as strange freaks of Nature. The limestones, interstratified with shales, give terraced and buttressed characteristics to the escarpments of the canons and narrow valleys.

Immediately south of Bitter Creek, on the east side of Green River, there is a small district of country which we have called the Alcove Land. On the east it is drained by Little Bitter Creek, a dry gulch much of the year. This runs north into Bitter Creek, a permanent stream, which empties into the Green. The crest of this water-shed is an irregular line, only two to four miles back from the river, but usually more than 1,000 feet above it, so that the waters have a rapid descent, and every shower-born rill has excavated a deep, narrow