STRATIGRAPHIC POSITION OF JUDITH RIVER FORMATION 539 
is based on lithologic character, stratigraphic sequence, the vertebrate and 
invertebrate faunas of the beds themselves, as well as on the paleontology of 
the underlying and overlying beds in both Canada and Montana." 
In discussing in another place? the areas in which Judith River 
beds occur, Stanton and Hatcher refer to the exposures near Havre, 
the eastward extent of which they did not determine, and say: 
It is very probable that this area is connected with the Cow Creek area by 
almost continuous exposures across the divide separating the drainage of the 
Missouri from that of Milk River east of the Bearpaw Mountains. On our 
journey from Havre to Cow Creek we passed through the eastern foothills of 
these mountains and crossed several areas of igneous rocks, but on Bean Creek 
near Lloyd post-office we saw outcrops apparently belonging to the Judith 
River beds, and zf our route had been a few miles farther east we could probably 
have had the formation in sight all the time.3 
This statement is a pure assumption, for it is evident that the 
beds were not traced continuously from the Milk River area to 
the vicinity of Cow Creek on the Missouri River, and the proba- 
bilities are that in this region to the eastward the distinction be- 
tween the Belly River and the Judith River formations and not 
their identity would have been clearly shown. It is more than 
probable that here is the point where the supposed correlation fails. 
The Belly River, the Judith River, the Lance, and the Fort Union 
formations all have their representatives in this area, which is one 
of great disturbance due to faulting and the occurrence of volcanic 
intrusions. The lithological resemblance between the strata of 
these formations has been noted by all who have seen them, not 
only in this region, but to the southward and also northward in 
Canada. The relations of the beds in this disturbed area will be 
determined only after a most careful investigation of the country 
surrounding the Bearpaw Mountains, extending far enough away 
from the mountains to give normal undisturbed sections which 
can be closely studied. A careful stratigraphic tracing of these 
beds in the undisturbed region, which cannot be made in a flying 
trip across the country, will also be necessary, together with accu- 
rate paleontologic collections and their careful study. 
t Science, N.S., XVIII (1903), 211-12. 
2 Bull. U.S. Geol. Surv. No. 257, 1905, p. 61. 
3 The italics in this quotation are those of the present writer. 
