532 AVC OViEARCE 
tion of arable land. Counting from the head of the Laramie Valley to Rock Creek, 
it is about 70 miles long, with an average width of about 25 miles, giving an area 
of 1,750 square miles. 
Thus there appear to have been two usages for the term ‘‘ Laramie 
Plains”—one in common use on the army maps and, to a greater or 
less extent, among the people, as is shown in official reports of the 
surveyor general of Wyoming;' and a second restricted to the portion 
east of Rock River (sometimes also given as Medicine Bow River). 
The term was not extended to the plains west of the natural western 
limit afforded by the West Rattlesnake Hills or Haystacks. Hayden 
used the term in both senses. In his report for 1868 he says: ‘In 
the Laramie Plains, along the line of the Union Pacific Railroad, 
extensive beds of coal have been opened, and the coal is used for 
generating steam and for fuel on the cars.” This is clearly a refer- 
ence to the mines at Carbon. 
In 1869 he said, in speaking of a trip from Fort Sanders to Fort 
Fred Steele: “Our course was along the Overland Stage Road just at 
the base of the mountains, on the south side of the Laramie Plains, 
from 5 to 20 miles south of the Union Pacific Railroad line.’’3 
In his report for 1870 Hayden used “‘ Laramie Plains” both in the 
limited and in the broader sense. Thus the statement that the 
‘entire surface of the plain east of the Medicine Bow forms one vast 
pasture ground” implies clearly that there are two portions of the 
plain, one east and one west of the Medicine Bow River.‘ 
The statement that the Laramie Plains ‘‘is usually understood to 
extend westward almost to the Medicine Bow River”’s is clearly the 
t Annual Report of the Commissioner of the General Land Office for 1871, 1872, p. 
271; seealso Fourth Annual Report, U.S. Geological Survey of Wyoming (1871), p. 251. 
2 Proceedings of the American Philosophical Society, Vol. X (1868), p. 467; [Second 
Annual Report, U. S. Geological Survey of the Territories, 1868] Report of the Com- 
missioner of the General Land Office for 1868, 1868, p. 233; First, Second, and Third 
Annual Reports, U. S. Geological Survey of the Territories for 1867, 1868, and 1869, 
p- 80. This statement should be compared with the statement on p. 89 of the last report 
(p. 242 of the original Land Office report), where it is stated that the Laramie Plains 
are 60 miles from east to west. This width, when compared with Thomas’ statement, 
places the western edge of the Laramie Plains near the North Platte River. 
3 Proceedings of the American Philosophical Society, Vol. XI (1869), p. 34. 
4 Fourth Annual Report, U.S. Geological Survey of Wyoming and Contiguous 
Territories (being a Second Annual Report of Progress), (1871), p. 79. 
5 Ibid., p. 121. 
