WARD,] PETRIFIED FORESTS OF ARIZONA. 325 
throughout the entire region and will be met with whatever route one 
may take, but there are differences in the degrees of abundance and 
of perfection or intensity of coloration of the wood at different points 
or centers of accumulation. The climax in all these respects, so far 
as has yet been discovered, is reached in an area lying between the 
Rio Puerco and the Little Colorado, but nearer to the former. It is 
bounded on the east by the meridian of 109° 45’ west from Green- 
wich, is nearly square, and its center falls in about latitude 34° 52’, 
longitude 109° 49’. Its western border is about 15 miles east of the 
junction of the two rivers and 17 miles east of Holbrook. Its north- 
ern boundary is 6 miles due south of the Rio Puerco at Adamana 
Station on the Santa Fe Pacific Railroad. The area is about 8 miles 
square and falls chiefly within township 17 N., range 24 E., but 
extends a short distance on the south into township 16 N., and on the 
west into range 23 E. 
This region consists of the ruins of a former plain having an 
altitude above sea level of 5,700 to 5,750 feet. This plain has under- 
gone extensive erosion, being worn down to a maximum depth of 
nearly 700 feet, and is cut into innumerable ridges, buttes, and small 
mesas, with valleys, gorges, and gulches between. The strata consist 
of alternating beds of variegated marls, sandstone shales, and massive 
sandstones. The marls are purple, white, and blue, the reddish tints 
predominating, the white and blue forming bands of different thick- 
ness between the others, which give to the cliffs a lively and pleasing 
effect. The sandstones are chiefly of a reddish-brown color and closely 
resemble the brownstone of the Portland and Newark quarries, or the 
red sandstone of the Seneca quarries on the Potomac River and at 
Brentsville in Virginia, but some are light brown, gray, or whitish in 
color. The mesas are formed by the resistance to erosive agencies of 
the massive sandstone layers, of which there are several at different 
horizons, and which vary in size from mere capstones of small buttes to 
tables several miles in extent, stretching to the east and to the northwest. 
The drainage of the area is to the south, and in the middle of it, 
having a nearly due southern course, but winding much among buttes, 
is the arroyo which has been mistaken for the famous Lithodendron 
Creek named by Lieutenant Whipple in 1853, as already explained. 
This arroyo or creek is dry most of the year, but has a gravelly bed 
often 20 feet in width, and, as with many other streams in this region, 
if holes are dug in this gravel to a depth of 4 or 5 feet water will 
accumulate and stand in them. 
The valley of this creek is narrow in the northern and central parts 
of the area and there are several short branches or affluents, but at 
the southern end it broadens out and its rugged, spurred, and canyoned 
slopes are highly picturesque. Here is located the principal petrified 
forest, and this is the region that has been characterized by some as 
