FEOM PRESIDIO DEL NORTE TO THE PECOS. 53 



At other places, however, all approach to the river, except hy the route of its dangerous channel, 

 is out of the question. 



Along the course of the river, the mountain barriers are occasionally pierced by side chasms 

 for the drainage of tributary mountain valleys. One of these is so remarkable as to deserve 

 some separate notice. 



At a point about seven miles from the entrance of the caiion, where the river is completely 

 hemmed in on each side by the largest development of the mountain range, being unapproach- 

 able except in boats from above, there is a cut-off on the American side, leading by an open 

 country over a gentle swell of ground, reaching the river about five miles below. This cut-off 

 passes directly at the base of the high mountains intervening between this route and the river, 

 having an average breadth of half a mile. At the summit of this swell is a depressed valley, 

 the drainage of which leads directly toward this mountain barrier in its course to the river. 



In following the dry-stream bed thus marked out, we find it entering by a narrow portal, 

 about 15 feet in width below, thence cutting its way by a uniform cleft through the entire 

 breadth of the mountains to reach the Rio Grande. 



It thus presents a miniature picture of the larger caiion made by the Eio Grande. Its floor 

 shows a smoothly-washed rock surface, in which basins frequently occur, bedded by washed 

 sand and pebbles, and receiving the limpid issue of a small trickling stream. In its general 

 course toward the river, it makes frequent zigzag angles, thus giving a new feature of scenery 

 at every turn, and presenting altogether a most varied combination of the grand, grotesque, 

 and beautiful. Along its sides is plainly observed a high-water mark, with an average 

 height of 15 feet above the rocky bed, indicative of the sudden floods, derived from copious 

 rains, to which this chasm is subject. This fact serves to give a somewhat nervous interest 

 to its exploration. The height of the perpendicular walls on each side, corresponding to the 

 thickness of the mountain range, is from 300 to 800 feet. The chasm thus formed opens up 

 gradually towards the summit, forming a broken yawning abyss, untouched by sunlight, and 

 having its depth exaggerated by the comparative dimness that shrouds it below. 



Thus sheltered from the sun's scorching rays, and cooled by evaporation from its brimming 

 basins of clear water, with its entrance fanned by a constant stream of cool air, this canon forms 

 a grateful retreat. Further toward the river the descent is made by several abrupt falls, form- 

 ing extensive basins below. These are filled with clear water, and offer natural bathing places 

 of a most attractive character. Its exit on the river presents the same general features of chasm, 

 the final debouchment being marked by a debris of rocks and pebbles, which project into the 

 main stream and form a difiicult and dangerous rapid. 



About three miles from this latter point, and twelve from the head of the canon, the main 

 development of the mountain range forming the Sierra Rica is passed ; the final exit is through 

 a narrow rocky portal, and presents the appearance of an immense gateway. The width of the 

 river at this point is barely 80 feet ; the adjoining mountain ridge on either side is so broken 

 and rugged as to be impassable for animals. 



On passing this narrow outlet we come upon a more open but still broken country, consisting 

 of basins of limited extent, set off with the usual form of gravelly table-land. The course of the 

 river is frequently obstructed by low rocky ranges, forming caiions ; again pouring out of these 

 canons into the more open basins, it becomes expanded, and forms limited sand beaches, patches 



