104 RECONNAISSANCE FROM CARROLL, MONTANA, 
although it makes no pretensions to topographical accuracy. The few bearings which were taken 
from Cone Butte are indicated. It isto be noticed that these mountains do not lie north and south 
on the east bank of the Judith River, where they are generally represented on the maps of this 
region. On the contrary, their trend is essentially east and west, so that the axis of the range lies 
almost at right angles with the course of the river. The general appearance of the range as viewed 
from a point to the northeast is shown in figure 6. 
Fig. 6 
i a 2 a ees 
Black Buttle. Cone Bestte. 
In the neighborhood of Box Elder, we pass, as has been stated, from the Tort Pierre clays to 
the sandstones of the Fox Hills Group overlying them. The rocks of this group extend widely east 
and west from this point, and from the hills which slope up to the foot of the Judith Mountains. 
Near Box Elder station, the sandstone shows itself nearly on the level of the stream at a point 
hardly a mile distant from it to the south. This is the locality where the fossils above mentioned 
were found. From this point, in approaching the hills, we took a course nearly south up a coulée, 
then dry, but which had been deeply excavated by running water, and which in the spring is no 
doubt a considerable tributary of Box Elder Creek. The eastern bank of this coulée is quite high 
above the bed, perhaps 200 feet, and all the way has a very uniform slope up to the mountains. 
On the west side the terrace is quite low, but has aiso the same gradual slope upward; the surface 
being for the most part remarkably level. The slope is about 50 feet to the mile. The sandstone 
of No. 5 is seen at a number of points, both in the bed of the coulée and above in the high eastern 
bank jast referred to. The slope upward on the east continues until within a mile or so of Cone 
Butte, where the sandstone strata are more upturned and the surface of the hill is more broken. 
Close to Cone Butte, at its foot (at ¢, fig. 5), we observed the sandstone, elevated 750 to 800 feet 
above Box Elder. It was here whitish, compact, weathering out into peculiar forms, with irregu- 
lar Jayers of ferruginous sand; dip, 10°; strike north 80° west. 
The thickness here, as elsewhere, is difficult to estimate, because of the insufficient exposure. 
It must be two or three hundred feet, or perhaps more. It may be mentioned here that the hills 
and terraces are so much covered with grass and soil that exposures of rock are rare. Below this 
point (at >, sec map) is an exposure of blue laminated clays, with abundant concretions, probably 
the Fort Pierre Group again, though here 600 feet above the highest exposure observed below, and 
400 feet above the sandstone identified as No.5 (a4, on map). The elevation is due to the uptuarn- 
ing of the mountains, involving both members of the Cretaceous alike. 
From here we made the ascent of Cone Butte. The immediate foot-hills, and indeed those at 
some distance from the peak, are made up of the talus from the mountain as far as the surface- 
exposure goes. Loose blocks of the trachyte, which forms the mass of the mountain, have been 
spread over the surrounding country to a remarkable extent, and the smaller fragments were found 
abundantly within a mile or two of Crooked Creek; that is, having crossed Box Elder Valley, 
Cone Batte is, as has been intimated, a trachytic hill, and according to the readings of our aneroid 
it is 2,200 feet above Box Elder, and 3,400 above the Missouri River. This is about the average 
height of what are called the Judith Mountains, though there are several points which are probably 
a little higher. 
The summit of Cone Butte commands an extensive view over the prairies to the north. The 
Little Rocky Mountains and the Bear’s Paw Mountains, though far in the distance, are the most 
conspicuous points to be noticed. Its commanding position is well appreciated by the Indians 
who use it as a lookout, for which it is most conveniently situated. A shelter which we found on 
the summit, formed of large flat blocks of trachyte resting upon the spreading branches of a stunted 
pine-tree, had doubtless been used as a resting-place by many an Indian scout. 
Cone Butte is itself a conspicuous object from all the surrounding country, even as far north 
as the Little Rocky Mountains; its perfectly conical shape being very striking from any point on 
the Carroll road. Viewed from the west, the sides of the cone are broken, and not so symmetrical 
as shown in figure 6. The slopes are covered with loose blocks of trachyte, and at some points are 
