108 RECONNAISSANCE FROM CARROLL, MONTANA, 
is the largest branch of the Judith River. This is a wide stream of clear, very cold, water, which 
takes its rise in a spring about five miles from where the camp is situated. The immediate valley 
of the stream is covered with excellent grass, and when the country becomes safe from the incur- 
sions of hostile Indians—far from being the case at present—it must prove of high value for 
settlement. 
About Camp Lewis there are considerable deposits of red clay. This is the case on both sides 
of the stream, but most conspicuously on the east bank, where the bluffs for a considerable dis- 
tance are of a deep-red color. It is rare to find any exposures of the beds which give rise to these 
red slopes. In general, they are so washed down that only the red surface-deposits are seen. In 
some ravines, however, on the east bank of Trout Creek, we found the hardened red clays in place. 
No fossils could be discovered, though they were searched for with care. These beds seemed to be 
somewhat irregular and of rather local character. In the place where opportunities for observa- 
tion were most favorable, we found 10 feet of red laminated clay, underlaid by a gray shale and 
overlaid by a sandy slate of a brown color. A little farther north, other layers of sandstone were 
observed, and beneath these some very thick bedded sandstone deposits; the red clays running 
out entirely. There was nothing to settle positively the age of these deposits. Except in color, 
they do not resemble the “red beds” of the West, generally referred to the Triassic; and as 
similar deposits were seen on the slopes of the Snow Mountains, twenty-five miles distant, overlying 
sandstones containing Cretaceous fossils (the same was true elsewhere), as noted later, it is more 
than probable that they are all Cretaceous in this vicinity. From this point, on our return journey, 
we made a detour and crossed the west end of the Judith Mountains; and, as we have just stated 
our observations in the neighborhood of Cone Butte, it may be interesting to add the others in this 
place. 
Passing on from the red beds just mentioned, we crossed a low divide, and came down into 
the wide valley of a branch of Trout Creek, passing over some more red clays at a little higher 
level than those seen before. From here, our course was about north; our objective point being 
some white limestone bluffs conspicuous on the summit of the range. The foot-hills first passed 
over consisted, as indicated by one or two rock-exposures, of a brown, firm sandstone, in which no 
fossils were found. It had a dip of 20° away from the hills. These hills, in both directions, are 
covered with timber and grass, and the rock is rarely seen on the surface. 
The limestone bluffs (1, fig. 5) were reached without much clue to the structure of the inter- 
vening country having been gained. This limestone stands up in a series of high buttresses, which, 
with their vertical fronts, are quite conspicuous objects. They show no evidence of stratification 
or structure. The rock contains occasionally masses of flint, though they are not so conspicu. 
ously cherty as those seen near Cone Butte. Some few fossils show that the rock is of Carboniferous 
age. 
The following is a list of those obtained : 
1, Zaphrentis centralis, Ev. & Shum. 
2. Syringapora mult-attenuata, McChes. 
3. Stictopora, sp. 
4. Spirifera centronata, Winch. 
On the hill to the west of this, a broad band of stratified limestone is exposed, in which some 
similar fossils were found. This same band apparently appears again on the north side of the bill, 
but here with a changed dip, northwest instead of southwest, pointing to a fold over at this point. 
We crossed the higher ridge here, from which we could see off to the east, noting, as before, 
that the hills to the north are mostly trachyte, while those behind them to the south are as uni- 
formly limestone. Near the source of Deer Creek, we descended into a broad, green meadow, quite 
surrounded by the hills. At one point, a patch of bright-red soil suggested a return to the red 
clays before seen. Crossing over by Bald Butte, a hill of trachyte, we reached the road again. 
The excursion was not altogether a satisfactory one, though showing the presence of the limestone 
at this point, but, as an investigation into the further structure of the hills, it was not successful. 
The difficulty lies in the fact that the hills are principally of igneous origin, and the thrusting in of 
the trachyte between the sedimentary rocks has destroyed the regular succession in the strata 
