1754 REPORT OF THE CHIEF OF ENGINEERS. 



Under the general name of the San Juan country, however, are commonly denoted 

 sections contiguous thereto, hut outlying the San Juan proper, such as the Summit 

 Mining District, Del Norte, and many other points. If, therefore, we liberally in- 

 clude the region west of the Sangre de Cristo Range as far north as Saguache, all of 

 which is directly interested in the industries of the mining country and is adjacent 

 thereto, we shall have, including but a small part of the Indian reserve, a total area 

 of 13,000 square miles, one-eighth of the entire State, and an area equal to that of 

 Massachusetts, Rhode Island, and Connecticut combined. 



Section II. — Its general character. 



For convenience of treatment of the San Juan proper, the main agricultural region, 

 watered by streams and rivers springing from the summits and flowing from the south- 

 ern and western trend of the range, all on the Pacific watershed, may be distinguished 

 as the lower country ; the rest the upper. In the former are included the valley of 

 the great San Juan River and those of its tributaries, the Navajo, the Blanco, the 

 Piedra with its branch the Nutria, the Los Pinos and its West Fork, or the Vallecito, 

 (he Animas with its affluent, the Florida, the La Plata, and the Mancos, all flowing 

 in a general direction to the south and southwest. 



The San Juan itself passes into New Mexico some 20 miles south of the Colorado 

 line, and after receiving the Animas and the La Plata, changes to the northwest, ap- 

 proaches so closely the point common to New Mexico, Colorado, and Arizona, that 

 after leaving New Mexico but little over two miles of Colorado soil is watered ere it 

 has entered the arid waste of Utah. 



That part of the Rocky Mountain system which is seen from the, great plains of 

 Colorado as we approach from the east, extending from latitude 38° 30' south to the 

 line of New Mexico, latitude 37° north, is known as the Sangre de Cristo Range. Its 

 name, the " Blood of Christ," arose from the prevailing color of the rocks, and was 

 given by the Spanish settlers of the country. Here and hereabout was formerly 

 drawn an ethnical line of settlement, which extended west through much of the San 

 Juan, as the general nomenclature will indicate ; almost wholly on the north are the 

 inhabitants Anglo-Saxons, while upon the east the rivers' names are chiefly of Spanish 

 origin, the Purgatoire excepted. The designation of this stream by some explorer or 

 immigrant in the language of lovely France has not been successful ; it is so written 

 or printed only, it is never heard or spoken, and instead of the name with a Parisian 

 accent or English signification, the stream is everywhere known as the " Picket- 

 wire." 



While it contains, it is said, the loftiest peak of the chain in the United States, known 

 as Sierra Blanca, 14,464 feet, a magnificent peak rising abruptly from the plain upon 

 which it stands, nearly 7,000 feet, the post of Fort Garland being at its base, the 

 Sangre de Cristo is not a part of the main continental divide, the great backbone of 

 the continent, for down its western slopes find their way streams that flow into the 

 Atlantic, tributaries of the Rio Grande. 



West of the range exists a great depression, the San Luis Valley, whose synclinal 

 axis lies slightly east of south and has the area of its upper part much contracted by 

 this mountain range in its westward tendency to meet the great continental divide. 

 From this point, the great divide, till its passage into New Mexico, assumes the shape 

 of a great V? with the vertex to the west ; the width at its mouth, the distance in an 

 air line from summit to summit being over a hundred miles. The Sangre de Cristo 

 slopes to the southeast, so that upon the border of New Mexico its mountain tops 

 are 80 miles east from the top of the great watershed, the most southern point of 

 the <. 



THE RIVERS. 



Springing from the very summits at the vertex of the divide, fed by banks of eternal 

 snow, is the Rio Grande, a clear and beautiful stream, flowing down to the east through 

 the center. Leaving the mountain slopes at Del Norte, it passes southeast and south 

 through San Luis Valley on its long passage to the sea, where it differs as radically 

 from its clear and lovely upper waters as do the country and climate from those of 

 its origin. 



The lower part of the < or great divide is known locally as the San Juan Mount- 

 ains, well named, for while their eastern slopes are washed by streams flowing to the 

 Rio Grande, of all the waters draining their western slopes, already called the "lower 

 country" of this region, the San Juan is the great receptacle. 



Close by the vertex' of the <, flowing south, is the Animas, rising a dozen miles to 

 the north in the Uncompahgre Mountains. Immediately to the west, beyond the divide 

 of the Animas, rises the Dolores, and hard by, scarcely 2 miles away, the San Miguel. 

 The latter flows directly northwest, emptying into the Dolores, which, passing south- 

 west and northwest in the shape of a rude JJ, lias traversed twice the distance of the 

 San Miguel, and is itself a feeder of the Grand in Utah. 



