378 C. R. Keyes — Ephemeral Lakes in Arid Regions, 



On the Jornada del Muerto and many other similar basins 

 there are slight depressions in the surface, which during the 

 rainy season collect the storm waters in sufficient quantities to 

 last several months. These ponds, which are frequently half a 

 mile across, are welcomed by the stockmen. 



Of similar character, but on a much grander scale, are cer- 

 tain ephemeral lakes which are known to have been formed at 

 a comparatively recent date. From the local reports concern- 

 ing some of these, there seems to be something of the mythical. 

 There are, however, several instances, which are well authenti- 

 cated, of the sudden formation of such lakes and their existence 

 through a period of years. 



One of these is lo«tated on the Mexican Central Railroad near 

 the station called San Jose, about 75 miles south of El Paso in 

 the state of Chihuahna, Mexico. This depression in the plain 

 had been reported in the past to have contained water at times. 

 The Rio Carmen, which runs west of Chihuahua and about 100 

 miles from San Jose, loses itself in the plain. Whenever there 

 are excessive rains, which are said to occur at rare intervals 

 along this stream, the waters form a lake often of considerable 

 size. When recently a lake of large size made its appearance 

 in a night, it was the first time in 15 years, according to the 

 raih'oad officials, that the phenomenon had occurred. 



Near Laguna station on the same line of railroad, 160 miles 

 south of El Paso, similar conditions obtain. A short time ago 

 the railroad company was compelled to move its track for a 

 distance of seven kilometers on account of the water rising in 

 the central depression in the bolson. Unusually heavy rains in 

 the mountains suddenly brought the water of the Sanz river 

 down in a body never before known. When the railroad was 

 located it was believed that it was at an elevation far above the 

 level of any possible "lake" waters, and far enough away from 

 any future shore line. 



In the famous Elephant Butte case which was fought through 

 the United States courts for so many years, some interesting 

 data bearing upon the subject in hand were brought out. One 

 instance is especially worthy of note. The state of Tamanlipas 

 is crossed by the Rio San Juan, a stream of considerable size 

 which flows into the Rio Grande at the city of Camargo. 

 Many years ago, according to the old man who was a witness 

 in the legal case, occurred a great flood in the San Juan valley. 

 It filled full the valley of the Rio Grande, broke over the foot 

 hills and made a long chain of large lakes, from which naviga- 

 tion of the Rio Grande lower down was carried on for a num- 

 ber of years. These lakes, wdiich were formed in dry desert 

 basins in the course of a few days, lasted for a period of 80 

 years. 



New Mexico School of Mines, Socorro, 

 July 1st, 1903. 



