Conrad T. Moore 
 
 
available for the Canadian valley route or other 
arteries lying further to the south. However, all 
were effective transects leading from the tall grass 
prairies to the semiarid bunch grass region--a 
situation not duplicated in the northern plains of 
the United States where the bunch grass-bounded 
Missouri River served as the primary route to the 
Montana gold fields and adjacent settlements. 
PRELIMINARY FINDINGS 
The effects of drought and grazing pressure by bison, 
antelope, prairie dogs, and grasshoppers on the plains 
grassland were recorded by forty-four travelers. 
While the relatively low number of such references 
can be attributed in most cases to a lack of 
occurrence of these processes along the routes 
taken, it was equally clear from the data provided 
that a significant number of travelers were unaware 
of the conditions present or failed to record what 
was observed due largely to an apparent interest in, 
or concern for, other aspects of their journeys. 
All but a few provided commentary on the abundance 
or lack of grass for draft, pack, or riding animals. 
However, the number who noted the location where the 
bunch grasses became dominant was even more 
restricted. Only twenty-two accounts contained this 
type of geographical information. 
Although data for the study were limited, the 
chronological distribution of citations involving 
drought, grass depletion by native fauna, and the 
location of grassland formations was sufficient to 
draw conclusions concerning the issues at hand. 
GRASSLAND STABILITY, 1806-41 
During the first three and a half decades of recorded 
observation, the central and southern plains 
grasslands appear to have been in ecological 
stability. Among the 50 travel accounts written 
during the period, only one drought and four 
cases of overgrazing were noted (Table 2). 
Table 2. Drought & Grazing Impact Occurrence 
Droughts & Grazing Impacts   1806-41 1842-60 1861-75 
 
 
Drought 
Overgrazing by buffalo 
Overgrazing by antelope 
Depletion by grasshoppers 
Depletion by prairie dogs 
 
 
1        8       0 
4      10        1 
0       1        0 
0       3        1 
0       3        0 
 
 
The drought mentioned by Jacob Fowler in 1822, 
appears to have been confined to the southeastern 
section of present day Colorado. 
Although seven travelers commented on grazing pressure 
by bison herds, three cases were clearly of moderate 
intensity. The four instances in which depletion was 
so severe that riding and pack animals suffered from 
malnourishment occurred prior to the drought. 
The fact that none of travelers crossing the plains 
between 1823 and 1841 experienced the effects of 
drought or overgrazing by native fauna appears to be 
particularly significant. During this period, the 
eastern limit of the bunch grass region was located 
to the west of the 100th meridian in the Arkansas 
 
 
valley and near the 101st meridian in the Platte 
valley--positions which generally coincide with 
the boundary currently recognized. 
ENVIRONMENTAL CHANGE, 1842-60 
The period 1842-60, was one in which the grassland 
was subjected to eight drought episodes and 
attendant depletion by native fauna. One process 
or the other was reported for all but five of 
the 19 years as the bunch grass region expanded 
eastward by more than 100 miles. 
DROUGHT 
Drought of varying severity was reported for 
different areas of the central and southern plains 
on three occasions in the 1840s and five during the 
period 1850-60. 
The drought of the spring and summer of 1842 in the 
western portion of the central plains appears to 
have been one of the most severe of the period. 
Fur traders at St. Vrain's Fort on the South Platte 
and Fort Laramie on the North Platte, whose 
experiences ranged back over the two preceding 
decades, stated to Captain John C. Fremont that 
"The present year had been one of unparalleled 
drought." Fremont's descriptions supported their 
assessments. 
Everywhere the soil looked parched and 
burnt; the scanty yellow grass crisped 
under the foot, and even the hardiest 
plants were destroyed by want of moisture. 
I was informed that the roving 
villages of Indians and travellers had 
never met with difficulty in finding an 
abundance of grass for their horses, and 
now it was after great search that we 
were able to find a scanty patch of grass, 
sufficient to keep them from sinking. 
Conditions experienced by emigrants and military 
escorts during the journey along the Platte and 
North Platte valleys in the spring of 1845 seem to 
have been somewhat less severe. Near the 100th 
meridian, Lieutenant J. Henry Carleton reported 
that "this year the unprecedented drought has so 
parched up the prairies, as literally to render them 
a desert, except immediately along the river." 
Evidence of the westward extent of the drought was 
provided by the emigrant, Joel Palmer. At a point 
about 20 miles northwest of Fort Laramie he stated: 
"The season has been so dry that [the] vegetation 
is literally parched up; of course, the grazing is 
miserable." Despite these adverse conditions, no 
loss of livestock was reported and none of the 
emigrants turned back, in contrast to experiences 
recorded during subsequent drought years. 
Effective drought of extreme intensity, resulting 
from an absence of precipitation coupled with hot dry 
winds and near-record temperatures was encountered 
by the Army of the West during the march up the 
Arkansas valley and through present day Otero County, 
Colorado, in the summer of 1846. Lieutenant George 
R. Gibson reported that "the season was an unusually 
dry one, and our suffering for water was often 
tormenting and painful." Temperature and wind 
conditions were noted by Sergeant Jacob S. Robinson. 
The country becomes a desert, extremely 
hot; the wind blows from it as from a 
heated oven, causing soreness of the eyes 
and bleeding at the nose. 
On the 4th of August we left the Arkansas,