Page 19 - The Geology and Ore Deposits of Sierra County, New Mexico - Bulletin 10

18 GEOLOGY AND ORE DEPOSITS OF SIERRA CO., N. M.
yellow pine, cedar, juniper, and other less valuable woods. In these parts timber has been cut in the past for mining and building purposes and for fuel. It is reported that the mining area near Hillsboro was at one time thickly covered with an excellent growth of yellow pine, which was cut off for use as mine timber and for fuel under the boilers ; now only an occasional rotted stump gives mute evidence of the former forests of the region.
But little farming in the Rio Grande valley is attempted in the northern part of the county, either around the lake or imme- diately below the dam. Slowly, however, these bottom lands are being reclaimed, and the population is growing. In the southern part, just above the little town of Derry, the highly cultivated area of the Elephant Butte project commences. Cattle raising on the higher plains and foothills is the main industry of the region.
PHYSIOGRAPHIC FEATURES DRAINAGE
The only permanent stream in Sierra County is the Rio Grande, which flows southward through the east-central part. From the north border to Elephant Butte dam, a distance of 24 miles, it forms the Elephant Butte reservoir of the Lower Rio Grande Conservancy Project. Below the dam the stream bends west and flows in this direction for nearly 6 miles. It then flows south to the southern border of the county near the town of Derry. Throughout its course it is situated to the west of the Fra Crisobal Range and of the Sierra Caballos.
Along the eastern border of the county and east of the Fra Cristobal and Caballos ranges is the broad desert valley named the Jornada del Muerto, or "Journey of the Dead," because of the dangers experienced by travelers crossing these waterless plains before the advent of the railroad. At the south end of the Fra Cristobal Range near Elephant Butte dam, at Palomas Gap, and again at the southern end of the Sierra Caballos, the west- ern rim of the Jornada is being dissected by the lateral tribu- taries of the Rio Grande.
The present valley bottom of the Rio Grande varies in width from 2 to 4 miles. In the spring the melting snows in the moun- tains of northern New Mexico and southern Colorado furnish an abundant supply of water, which is caught and stored in the reservoir. Since the building of the dam, the danger from periodic floods in the spring and summer months has been prac- tically eliminated, and in the lower valley the amount of water flowing may be closely controlled at all times.
The western part of the county is drained by a number of eastward-flowing tributaries of the Rio Grande. From north to south the important ones are Alamosa River, which drains territory to the north through Canada Alamosa near Monti-