124 RECONNAISSANCE FROM CARROLL, MONTANA, 
once more reversed, forming apparently a final fold in our series, though the inclination is so slight 
that the direction remains uncertain. 
Our course along Flathead Creek was very nearly at right angles to the prevailing direction of 
the strike, so that we had a very good opportunity to observe the relations of the successive folds. 
FROM ARMELL’S CREEK TO THE MOUTH OF THE JUDITH. 
From our camp on Armell’s Creek, a short excursion was made to the mouth of the Judith 
River; the intention being to make such examination of the country at that point as our limited 
time would admit of. 
The beds at the mouth of the Judith have been explored only once before (by Dr. Hayden), and 
their age has hitherto been in doubt. We were able to remain but two days in this interesting 
locality, and the results obtained were of course meager. Enough, however, was seen to establish 
the age of the beds at this point as beyond a doubt Cretaceous; three members of this division of 
Mesozoic time having been found there and identified by fossils. 
The ravines, which occur so constantly along the Missouri, extend back from that stream but 
a few miles, except where a river enters it. Tributaries, however, carry the ravines and the accom- 
panying Bad Lands back, sometimes to their sources. The country which may properly be consid- 
ered as Bad Lands near the Judith is quite extensive, and is of the most rugged and barren char- 
acter. Each little stream that flows into the Missouri is bordered by a strip of country more or less 
wide, that is gullied and washed out in deep and precipitous ravines, without vegetation, and 
venerally utterly impassable, except for the bighorn or the wolf. 
The Bad Lands on the Judith River extend along that stream for about twenty-five miles from 
its mouth, and run back from the river for about five miles on each side of the stream. Those on 
Arrow Creek, which flows into the Missouri a few miles west of the Judith, extend along it for ten or 
twelve miles back from its mouth, and have an average breadth of four miles on each side of the 
stream. Those on Dog Creek stretch back into the bluffs for about fifteen miles, ranning over to 
meet those of the Judith for about six miles of this distance, and reaching eastwardly nearly over 
to Armell’s Creek, which also has an extensive system of Bad Lands. 
The rocks are chiefly sandstone, quite pure, often quite hard, but occasionally so soft as not 
to cohere in blocks when removed from the beds. Occasionally, thin beds of an arenaceous lime- 
stone are seen, and from these a few fossils may generally be obtained. Yellowish sandy clays and 
inarls also occur toward the base of the bluffs, but without fossils, as far as could be seen, and lack- 
ing any distinctive features. Much of the lower portion of the bluffs is concealed by deposits of 
the Fort Pierre beds, Cretaceous No. 4, which occurs all along the Judith River bottom and in 
many of the ravines, sometimes running far back into the bluffs. These beds agree in all respects 
with the deposits of that age seen near Carroll, Crooked Creek, and Box Elder. They were the 
same dark shales, containing the limestone concretions, with Baculites, &c., and abounding in the 
glittering selenite crystals that seem to be peculiar to these beds. 
From our Camp on Armell’s Creek, we followed the Helena road back toward Camp Lewis for 
five miles or more, and then, leaving it, took a course a little west of north, and, passing about ten 
miles to the eastward of the Moccasin Mountains, struck the divide between the Judith and Dog 
River, by which road alone our point of destination could be reached with the wagons. The time 
occupied in reaching our camp on the Judith was two days; the distance traveled being a little 
more than forty-five miles. 
At a point two miles north of our camp, on Armell’s Creek, an exposure of bare bluffs was 
noticed, which furnished the following section, from below upward : 
Feet 
Dark-gray horizontally-laminated shales. ...-. 2.2... 2.0... .2 cee eee e eee eee - 60 
Laminated slightly ferruginous sandstone. .........-.-..5. 202. ees ee eee eee eee 12 
Soft, whitish clays, about ....-..--..-.-2220 22sec nee cee eee ee eee ee sees 100 
Dark-gray clays, interstratified with layers of impure limestone concretions, 
about ....-...--.--- wie eieseee 23 EE See RE eee PET Te Per een rire 100 
