OCR Text |
Show 89 portion of the divide forming this cul- de~ 8ac} with its slopes, may be subdivided for the sake of description into three divisions: 1st. The northern, extending from the Cochetopa Pass to the depression at the head of the western tributary of the Cebolla Creek. 2d. The bottom of the Loup, extending from this depression to the pass at the head of the Rio los Piuos; and 3d. From the headwaters of the LosPinos to the Sierra San Juan and the Summit mining- district southwest of Del Norte. About the bottom of the Loup are numerous short ranges, determined by the gorges and call on s of the streams flowing from them, which, for convenience and because they are connected intimately with this portion of the divide, will be described in full with it. The first and third of these divisions are similar, inasmuch as they exhibit more clearly the plateau character of the volcanic overflow reft by the cation of the Upper Rio Grande, and cut out by water and ice into cafions and gorges, until now portions of the plateau exhibit mountain- peaks and short ranges. This first division, however, more distinctly retains its plateau- like character. Beginning at the Cochetopa Pass, the summit of the divide gradually increases its height from 10,000 feet at the pass to approximately 13,600 feet at the head of the Saguache, exhibiting the character already described in speaking of the western rim of the San Luis Valley. The east branch of the Saguache heads in tremendous cup- like cavities and box- canons under mesa- like portions of this plateau, which hero may be followed for miles around the headwaters of the Saguache, La Garita, Carnero, and Embargo Creeks, upon nearly a flat surface, strewn with trachytic rocks, and covered, where decomposition of these rocks has sufficiently taken place to furnish a soil, with a thick mat of Alpine grasses and flowers. Upon the Rio Grande side the descent from the head of the Saguache to the river, a few miles distant, is very abrupt; here vertical ledges and bluffs close in upon the river and form the narrow and short cation called Wagon- wheel Gap, 30 miles above Del Norte. From the heads of La Garita and Embargo Creeks, where the flat mesa- like surface ends, eastward to the San Luis Valley and southward to the Rio Grande, the conn try breaks down in detached hills and bluffs, and near the valleys sharp points or cerritos of basalt. West of the deep crateriform cavity, in which heads the eastern of the two main branches of the Saguache, the plateau is crowned by a short ridge of volcanic material, curving sharply down to the . surface of the grassy plateau in steep slopes of loose fragments to the south, and inclosing in perpendicular walls, in semicircular sweep to the north, the headwaters of the main or western branch of the Saguache. These peaks surmount the plateau for some 12 miles farther west, several ot them approaching 14,000 feet in altitude, and end in conical masses which slope gradually down to the upper surface of Bristol Head, a plateau- mountain V- shaped in plan, the opening of the V turned to the north and the vertex near the Rio Grande. This mass is of, perhaps, 30 square miles' area, bounded by a vertical blnff from 2.500 to 3,000 feet on the southwestern side of the V, and by slopes more or less gradual or abrupt on the eastern. It is nearly 13,000 feet in altitude, and a marked feature of the landscape. It is composed mainly of a brownish trachyte. The country to the north of these peaks slopes down to the Gunnison, the slopes being cut by the cations of the Cochetopa and Cebolla and their tributaries into subordinate ridges of not great height, and eveu crest. West of the Bristol Plateau and the peaks standing upon it as a pedestal, there is a depression extending some eight or ten miles about the heads of western forks of the Cebolla, a great part of which is below timber- line. Being rather imperfectly drained, it is covered bv numerous marshy spots. From the lowest part of this depression, over which the Indian trail from the old Los Pinos agency crosses into the Rio Grande Basin, the country- a rolling series of hills well grassed- slopes gradually upward to the rim of the Clear Creek Basin, which also forms the western wall of the cation of the Lake Fork of the Gunnison. A break in this latter rim at the headwaters of the western branch of the Cebolla offers a passage- way for the new wagon- road, which leaving the valley of the Rio Grande under Bristol Head, first crosses the Atlantic and Pacific divide to this branch of the Cebolla, which it follows to its head and over the break mentioned to the canon of the Lake Fork. North from this breaks a ronnd-topped, rolling stretch of elevated country, ranging in altitude above sea- level from 12,000 to 12,800 feet, and named by us the Cannibal Plateau- in memory of the horrible butchery and acts of cannibalism which were practiced under its western edge in 1874- extending for about twelve miles, through the eastern slopes of which the Cebolla, which has first collected the numerous branches flowing down from the mountains north of Bristol Head, cuts a formidable cafion. From a few miles south of the Cochetopa Pass, around this northern rim of the Rio Grande Lonp to the depression northeast of Bristol Head, or for the entire portion of this rim in the first of the divisions into which this loup is divided, the range is impassable, transversely, for other means of transportation than lightly- laden pack- mules, and for those in but very few places. |