Parks of Colorado. 359 
vanna deposited from the filtration of the waters, highly impreg- 
nated with the mountain debris. Beneath this soil is a contin- 
uous pavement of peat, which maintains the saturation of the 
- Super-soil, and is dha: for fuel. 
+he middle region of the plain, longitudinally, displays a era- 
ter of the most perfect form. The interior pit has a diameter 
of twenty miles, from the center of which is seen the circum- 
ferent wall forming an exact circle, and in height five hundred 
feet. This wall is a barranca, composed of lava, pumice, calcined 
lime, metamorphosed sandstone, vitrified rocks, and obsidien, 
This circumferent barranca is perforated through by the entrance 
a 
res 
7} phere, It is beveled by these forces to a perfect level; is of the 
_ fattest fertility, and drained through the porous formation which 
erlies it. 
lal course is confined in a profound chasm or cafion, of per- 
pendicular walls of lava, increasing to the depth of 1,200 feet, 
Where it debouches from the jaws of this gigantic flood of lava, 
hear the village of La Joya, in New Mexico. Such are the ex- 
Taordinary forms and stupendous dimensions with which nature 
here salutes the eye and astonishes the imagination. The ex- 
| Pansion of the lava is all to the south, following the descent 
| ‘ward the sea. Toward the north, repelled by the ascent, are 
} Waves demonstrating the defeated effort to climb the mountain 
Such is an imperfect sketch of this wonderful amphitheater 
| of the Sierras. tis physical structure is infinitely complex, ex- 
. hibiting all the elements of nature piled in contact, yet set to- 
