RECONNAISSANCE OE THE BOOK CLIFFS COAL FIELD, 
BETWEEN GRAND RIVER, COLORADO, AND SUNNY- 
SIDE, UTAH. 
By G. B. Richardsox . 
INTRODUCTION.' 
The Book Cliffs coal field is part of the southern rim of the Uinta 
Basin, which is an immense structural trough in western Colorado 
and eastern Utah, around whose margin the outcrop of coal-bearing 
rocks can be traced for more than 500 miles. (See fig. 1.) From 
the vicinity of Mount Ililgard, in central Utah, northward to Castle- 
gate, the coal measures form the eastern escarpment of the Wasatch 
Plateau. Thence they trend southeastward to Grand River, out- 
cropping in the Book Cliffs. Beyond Grand River they continue 
eastward, forming the southern face of Grand Mesa, to the vicinity 
of ('rested Butte. From this point the coal-bearing rocks trend 
northward and cross Grand River again near Newcastle. North 
of Grand River they form the Grand Hogback, and beyond the Dan- 
forth Hills the trend is westward along the southern ilank of the 
Uinta Mountains. This great basin of coal-bearing rocks has been 
but partially prospected, and mines are in operation in only a few 
localities, but enough of the area has been explored to prove that 
it is one of the most important coal reserves of the Rocky Mountain 
region. As a whole, this area is a distinct unit, but for convenience 
of study and description, it is divided into several parts. The Book 
Cliffs field is that portion of the southern rim of the Uinta Basin 
which includes the Book Cliffs and lies between Grand River, Colo- 
rado, and the Wasatch Plateau, Utah. 
The geology of the Book Cliffs was first studied by A. C. Peale, 6 
of the Hay den Survey, who in 1876 examined the eastern part of 
the field. The western part was included in G. II. Eldridgc's map 
of the Uinta Basin published in connection with his study of asphalt 
and bituminous rock deposits. ' Until recently these papers have 
a An abstractof this repor! was printed in rontributions to Economic Geology. 1906, Pari II: Bull. U. S. 
Geol. Survey No. 316, 1907. 
i> I'e.ale, A. C, Geological report on the Grand River district: Tenth Ann. Rept. CJ. S. Geol. and Geog. 
Survey Terr., 1878, pp. 170-185. 
'Eldridge, G. TL, Asphalt and bituminous rock deposits of the United States: Twenty-second Ann. 
Rept. U. S. Geol. Survey, pt. 1. 1001. p. 332. 
