THE RELATION OF ALLUVIAL TERRACES TO MAN. 45 



northwestward past the Indian agency of Mescalero, then westward and finally south- 

 westward to the edge of the escarpment, where it debouches upon the plain of the Otero 

 Basin. Throughout its course it is characterized by alluvial terraces. In the upper /more 

 mountainous portions of the valley the number of terraces reaches five, while lower'down 

 the number diminishes. At the present time no continuous stream flows from end to end 

 of the valley, although temporary streams flow for short distances here and there. At 

 some earlier time a continuous stream probably flowed the entire length of the valley, 

 for the main terraces are well developed and continue many miles, as if cut by a strong 

 flow of water. When such a flow existed the valley bottom was doubtless occupied by a 

 gravelly river channel having a regular, graded slope from end to end. Now, however, 

 under the influence of the last epoch of relatively intense aridity, the valley floor has been 

 filled with alluvium in such a way as to produce well-marked irregularities. Wherever a 

 tributary has brought in an unusually large amount of waste, the feeble stream of the main 

 valley has spread this downstream for a short distance, but has been unable to carry it 

 away. In the deep deposits of silt and gravel thus formed the water of the main stream 

 sinks into the alluvium and disappears, only to come to the surface once more at some 

 pouat where the depth of the alluvium is less. In this way, as will readily be seen, the 

 valley bottom has been divided into a series of relatively level portions where abundant 

 alluvium has been deposited, and a series of relatively steep slopes where the abundant 

 supply of alluvium has ceased and the stream which should carry it away has disappeared. 

 Often, as one rides down the valley, a plain a quarter to a half mile wide and several 

 miles long is encountered, which seems at the lower end to drop off almost in a slope that 

 would be called steep. The effect, indeed, as one looks down the valley from the middle 

 of the plain, is as if the bottom of the valley were genuinely dropped down to a lower level. 

 Even to the unscientific observer it is manifest that if the supply of water should be sufficient 

 to maintain a continuous stream, erosion would at once attack the steep slopes between 

 the plains. As a matter of fact this process has already begun within the last 2 or 3 decades. 

 At various points deep guUies, one of them with a depth of nearly 50 feet, have been cut, 

 and a series of years of heavy rainfall would cause them all to be prolonged, both upstream 

 and down, until a continuous gully was formed. The succession of events here is exactly 

 the same as in the Santa Cruz Valley, near Tucson, hundreds of miles to the west. The 

 chief difference is that here the part played by man is relatively unimportant : even without 

 man's intervention cHmatic forces have begun to form a terrace. Apparently the last 

 quarter of a century, from about 1885 onward, has been a period when heavy rains were 

 on the whole more numerous than for many decades, or possibly several hundred years 

 previously. 



In ancient times the Tularosa Valley contained at least two villages. One of these 

 was located in the broadening of the valley where the Mescalero Indian agency employs 

 about 20 white men and women to take care of about 350 semi-nomadic Apache Indians. 

 The old village probably contained quite as many people as the modern agency, and 

 possibly more, for traces of pottery can be seen on both sides of the valley. The other 

 village, which I did not visit, is said to be located about 12 miles below the agency and 

 5 miles above the modern village of Tularosa, which lies out in the plain at the mouth 

 of the Tularosa Valley. Ruins are described in the plain also, but they are beyond the 

 limits of our present investigation. 



Nearly 2 miles below the agency the valley bottom is broken by one of the relatively 

 steep slopes described above. The plain below the slope is quite flat and almost swampy. 

 It is cultivated, however, by means of irrigation from a small spring, and with a little 

 more care could easily be made highly productive. On either side the plain is bounded 

 by gravel terraces, 20 or 30 feet high. At the base of the northern terrace, near the upper 

 end of the plain, Mr. A. M. Blazer, who lives a little way up the valley, pointed out the 



