396 Mesozoic Rocks of Colorado. — Stevenson. 
son, Topeka & Santa Fe railroad passes from the Pecos river 
near San Miguel almost to Lamy or Santa Fe junction. 
Should one rise upon the bluff, taking the old road from San 
Miguel to Galisteo, he would cross the whole of the Dakota , 
the Fort Benton and the Niobrara before reaching the latter 
village. 
In the report on the geology of this region, 1 the writer re¬ 
ferred this whole succession to the Dakota , because it is evi¬ 
dently the Dakota of Colorado northward greatly expanded ; 
but while so doing, made the remark that the whole series 
may be Triassic or may be Cretaceous , the grouping having 
been made simply for convenience. This remark was too 
narrow, as it left the Jurassic out of consideration. As the 
Dakota in Colorado rests on rocks clearly Jurassic , there is a 
possibility that some portion of this may belong to the Jur¬ 
assic. But the writer is inclined rather to look upon it all as 
belonging to the Cretaceous. Mr. Marcou would place it all in 
the Jurassic while others would place much of it in the Triassic. 
This question must be settled by some geologist sent in with 
time at his disposal, whose studies will not be in reconnais¬ 
sance but be detailed. Every one, who thus far has touched 
the region, has studied the geology only in haste or as inci¬ 
dental to other work. The differences of opinion during late 
years, doubtless, owe their origin largely to this. There may 
be much of right in all or much of wrong in one. The wise 
man is he who possesses his soul in patience, for fierce invec¬ 
tive and personal abuse have not yet become accepted or con¬ 
vincing arguments in stratigraphy. 
But be all that as it may. The section at Galisteo can be 
duplicated, below the Laramie , at more than sixty miles 
northeast along the 36th parallel from Coyote to the Canadian 
hills ; and this again by following the same parallel from the 
Canadian hills to the bottom of the Canadian canon, though 
the very lowest beds of the Lower Dakota are not reached in 
the canon at that point. Ascend the canon to the old Leav¬ 
enworth crossing, 21 miles further north; there, near the 
mouth of Cimarron creek, one is again on the Fort Benton. 
The rest of the section to the top of the Laramie is exposed on 
this stream. The Galisteo section can be duplicated at any lo- 
1 U. S. Geographical Surveys West of 100th meridian, vol. in, 
Supplement, chap. vn. 
