86 RIO GRANDE COAL FIELDS OF TEXAS. [bull. 164. 
"the San Carlos topographic sheet for the United States Geological 
Survey, states that work in this shaft has been abandoned. The second 
working was along a slope on the side of the mountain, a little less 
than a mile and a half slightly south of east from San Carlos. It has 
been reported that the mine here has been abandoned. There are other 
outcrops of coal on the side of the mountain and along the courses of 
some of the arroyos in the basin. 
Mr. G. N. Marshall, chief engineer of the Rio Grande Northern 
Railroad, informed the writer that coal also outcrops on the western 
slope of the Vieja Mountains, in the valley of Van Horn Creek, but 
that it had not been found in commercial quantities. The inference is 
that coal will be found here, as lower geologic horizons are exposed 
along that creek and between it and the mountain. 
Coal has been reported from several other localities in Trans-Pecos 
Texas, but so far as ascertained they have been neither prospected nor 
investigated. These localities are: El Paso County, 1 Eagle Springs, 2 
between Sierra Barda and the Rio Grande, 3 and between Alpine and 
Paisano Pass. 4 Mr. R. T. Hill, who has recently made an expedition 
into the Great Bend country of the Rio Grande, furnishes the follow- 
ing note: a On the east and south side of the Chisos Mountains there 
are extensive areas of the Montana formation in which there are 
coal beds of unknown value." 
Although the coal fields of western Texas have been little explored, 
there are indications that there are several occurrences of poor coal in 
the region. 
The Cretaceous coals of Colorado are, according to Hills, 5 practically 
all of Laramie age, i. e. , they belong to a horizon above the Pierre or 
Fox Hills. The Texas Cretaceous coals are geologically older than 
the Colorado coals. 
1 C. A. Ashburner, Mineral Resources U. S. 1885, p. 68. 
2 W. M. Chandler, Mineral Resources U. S. 1886, p. 350. 
3 W. H. von Streeruwitz; Fourth Ann. Rept. of Geol. Survey of Texas, Austin, Texas, July, 1893, p. 175. 
4 W. H. von Streeruwitz; loc. cit. 
& Mineral Resources U. S. 1892, pp. 319-324. 
