129 — 
the valley of the Mississippi.and the north Pacific, justifies a precise notice- 
of its locality and distance from/leading points, in addition to this statement 
of its elevation. As stated in the report of 1842, its latitude’at the point’ 
where: we crossed is'42° 24' 32"; its longitude 109° 26' 00"; its distance 
from the mouth of the Kansas, by the common travelling route, 962 miles; 
from the mouth of the Great Platte, along the valley of that river, according 
to.our survey of 1842, 882 miles ; and its distance from St. Louis about 400° 
miles more by the Kansas, and about 700 by the Great Platte route 3; these 
additions being steamboat conveyance in both instances. From this pass. 
to the mouth of the Oregon is about 1,400 miles by the common travelling 
route; so that, under a general point of view, itmay be assumed to be about 
half way between the Mississippi and the Pacific ocean, on the common: 
travelling: route. Following a hollow of slight and easy descent, in which: 
was very soon formed a little tributary to the Gulf of California, (for the: 
waters which flow west from the South Pass go to this gulf,) we made our. | 
somely timbered with cottonwood. The refreshing appearance of the broad © 
river, With its timbered shores and green wooded islands, in contrast to its 
dry, sandy plains, probably obtained for it the name of Green river, which 
was bestowed on,it by the Spaniards who first came into this country to 
trade some 25 years ago. It was then familiarly known as the Seeds-ke- 
e-agie, or Prairie Hen (/etrao urophasianus) river; aname whieh it re- 
ceived. from the Crows,to whom its upper waters belong, and of which this. 
* bird is still-very ayundant. . By the Shoshonee and Utah Indians,to whom: 
belongs, for a considerable. distance below, the country where we were now’ 
travelling, it was called the Bitter Root river, from the great abundance in 
its valley of a plant which affords them one of their favorite'roots:.. Lower 
down, from Brown’s‘hole to the southward, the river: runs through lofty 
chasms; walled in: by precipices of red rock’; and even ‘among-the wilder 
tribes who inhabit that portion of its course, I have heard itealled by Indian 
refugees from the Californian settlements the Rio Colorado.’ We halted to 
noon at the upper end of a large bottom, near’some old houses, which had” 
beema:tradins: post, in latitude 41° 46° 54". “At this place the elevation of — 
the tiver above the sea is 6,230 feet: That of Liewis’s fork of the Col ae 
at Fort Hallis, according to our subsequent observations, 4,500 feet. "Fire 
» descent of each stream is rapid; but that of the Colorado is but little known, - 
and» that: little derived: from vague report. Three hundred milés* of tS” 
¥ part, as it approaches'the gulf of California, is reported to be smooth 
and*tranquil; but its upper part is manifestly broken into™many falls 
9 J F 
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aiiten” 
