1881. 19 WF GUSS IN: Vin PAC HSGe 
beds, having a general northeast and southwest d-rection. In Wil- 
barger County the gravel drift is in great quantity, and boulders from 
three to seven inches in diameter occur. In places, and having a north- 
east and southwest bearing, heavy deposits or lines of gravel and 
boulders attract attention, appearing as though a great flow towards 
the southeast had met obstructions along its course, the great incline 
of this region being directed towards the southeast. Beyond Pease 
River the gravel drift lessens, but the large boulders are occasionally 
seen as far west as the gypsum hills. Not far north from the centre of 
Hardeman County I again found the Haskell County copper bed, the 
accompanying sandstones being thin and much mixed with gypsum. 
The copper bed reaches higher than the surrounding country, except 
the gypsum hills tothe west. From this high locality of the copper, 
known as Prairie-dog Mounds, the country inclines on one side north- 
ward to a creek emptying into Red River, and on the other side south- 
ward to the Pease River. South of these mounds, where only here and 
there patches of thebed are preserved in the midst of a general erosion, 
I found the largest mass of copper ore thus far discovered, consisting 
of an aggregation of cuprified wood, resembling the trunk of a tree, 
more than one foot in diameter. 
Beyond Red River, the bed continues to the vicinity of the Salt 
Fork of Red River, distant but little over 20 miles from the 
Wichita Mountains of the Indian Territory. The bed probably con- 
tinues nearly to the western end of these mountains, and here must be 
found the true centre of elevation and the origin of the gravel drift. 
The Haskell County copper bed was also traced south to the Wichita 
River, thus establishing its continuity from the southern portion of 
Haskell County, through Knox and Hardeman Counties, into the Indian 
Territory, a length of more than Ioo miles. Subsequently, the northern 
end of the bed was found a short distance from the western end of the 
Wichita Mountains, on the south side of the range. The copper forma- 
tions of Archer and Wichita Counties continue through Clay County 
to the Red River boundary of the Indian Territory. The gravel drift 
does not extend to the north of the Wichita Mountains, but a limestone 
district occurs, about 20 miles in width, that reaches probably as far out 
to the north, from the Wichita Range, the course of the latter being 
east and west. This limestone area may be called mountainous, is 
much disturbed and tilted, and is similar in appearance to the metalli- 
ferous limestone tormation of Mexico. The Wichita Mountains are 
mainly made up of porphyries, trachytes and basalt, and appear to be 
two parallel ranges with transverse ranges and small valleys between. 
About 12 miles west of Fort Sill an extensive body of hornblende slate 
makes its appearance between the two main ranges. The drift from 
