1764 REPORT OF THE CHIEF OF ENGINEERS. 



oats is remembered to have failed to ripen and, damaged by early frosts, was harvested 

 in the stalk. There was, however, some exceptionally severe weather early in the 

 season, and on the 18th of September nearly 10 inches of snow fell, the storm cover- 

 ing- a very great area in both Northern and Southern Colorado, including the plains. 

 The year previous, we were informed, a similar crop had matured and was success- 

 fully harvested. 



As the altitude is increased, the diurnal range of temperature is greater, and hence 

 the danger from early frosts. 



The agriculture of the San Juan is as yet in its primitive stage, almost all the atten- 

 tion and capital of the country having been concentrated in mining interests. 



The San Luis Valley bears witness to the wealth of the produce returned by the 

 soil under proper cultivation. In following up the Rio Grande, the Mexicans have 

 ascended divers tributary waters, and upon these and aloftg the main river can their 

 apologies for farms be seen. Generally content with simple existence, but little vari- 

 ety in the produce of their lands is observed. The turning of the soil with oxen and 

 a sharpened stick, the thrashing by flail and trampling under foot, and the crushing 

 of the grain between stones can be so frequently seen, that the charm of novelty is 

 lacking and one's curiosity is soon satiated. Progress is not their hope or desire, and 

 content to eke out a bare subsistence, their ambition does not extend beyond a baile, 

 or the tripping of the "light fantastic," with surroundings that are here, as a rule, far 

 from enchanting. Their cultivation of the soil tells of Eastern origin and traditions, 

 and is by irrigation from acequias or ditches. Smaller ditches at intervals lead out 

 from the main, being connected by parallel ones thereto ; furrows of earth of varying 

 height are raised at stated points xiarallel and perpendicular to one another, cutting 

 up the entire area into many patches nearly square and of small extent. With the 

 planting of the seed and the main ditch filled, all the smaller outlets and various sec- 

 tions being simultaneously overflowed, the entire area is carefully submerged, the 

 little furrows confining the water in each section. To the inexperienced farmer the 

 first successful irrigation of his land is a matter of considerable labor and pains. 

 Besides the thorough moistening of the earth obtained by the gradual settling of the 

 waters, a fertilizing process is at the same time insured. These streams carry in solu- 

 tion much rich and valuable material from the denudation of sections drained in their 

 passage, which is left in deposit like a superstratum of manure. The latter is never 

 used, the farmer depending upon irrigation for the supply of those constituents ex- 

 tracted from the soil in the growth of produce. 



The Rio Grande descends from 7,750 feet at Del Norte to 7,400 on leaving the State 

 for New Mexico. Upon its western side numbers of locations are along the Piedra 

 Pintada, which sinks a few miles from the Rio Grande, the Alamosa and La Jara, but 

 chiefly along the Conejos, the most thickly-settled of all its tributaries; upon the east- 

 ern are the Trinchera, Culebra, and Costilla, the Culebra above San Luis being on this 

 side the seat of largest habitation. 



In the upper part of San Luis Valley is situated the finest land of that section. 

 With the mountain range encircling it upon the east, north, and west, exposed only 

 upon the south, whence do not come the heavy snow-storms and coldest winds, it con- 

 tains the finest land for cereal and other productions. Drained by the San Luis Creek 

 and the Sawatch, its tributary, the ranchmen who have located along the streams 

 have been rewarded for their labor by very abundant crops of all kinds. Through- 

 out the valley large herds of cattle find ample sustenance, the property mainly of 

 Americans, while numerous herds of sheep of Mexican ownership are driven to and 

 fro; 



The valley of the Conejos, with its affluents, the San Antonio and Los Pinos Creek, is 

 a most fertile region. Several miles east from Conejos, during the high stages of the 

 rivers in June, water from the San Antonio finds its way into the former river above 

 the latter's mouth, forming an island. This section is especially rich and there exists 

 almost a natural irrigation, the Mexican ranchmen raising large crops of all kinds at 

 the cost of but little labor therefor. Of all the regions west of the Rio Grande, that 

 from the Conejos to the La Jara is the most desolate, and for ten miles of the way 

 from the Conejos, while the hardness of the fragmentary volcanic rock of which it is 

 constituted made it the finest of roadways, all other conditions combined to render 

 it in June and July naught save a waste and desert. 



The sage-brush and greasewood which elsewhere grew knee and waist high, was 

 here literally burnt out to 8 or 10 inches, never exceeding a foot. This was very limited 

 in quantity and was all that existed of a general vegetation. Now and then was seen 

 a solitary flower, evidently lost from its brethren, with but an occasional cactus or 

 "soap-weed," the average being not over an inch of vegetation to the square foot. 

 Fragments of lava, basalt chiefly, and some trachyte were everywhere about. The 

 reflected air, heated and burning the face and filling the lungs, was almost parching. 

 Not a single insect was observed, hardly a blade or tuft of grass in a mile. Even all 

 the feathered tribe avoided this barren place, no birds whatever being noticed save the 

 horned lark and a single sparrow near its edge. Passing over this desolate region, 



