98 GUIDEBOOK OF THE WESTERN UNITED STATES. 
traders, and scouts of the Rocky Mountain region from 1830 to 1870. 
His visit here is perpetuated by the names Bridger Range, Bridger 
Peak, and Bridger Creek. 
Recently an effort has been made to apply the name Sacajawea 
Peak to one of the peaks in the Bridger Range, in honor of the Indian 
woman who accompanied Lewis and Clark in their journey to the 
Pacific coast and return and who guided Clark through the Bozeman 
ass. 
The Bridger Range, which is a conspicuous feature from the 
vicinity of Belgrade, consists of the upturned edges (see fig. 17) of 
the rocks of the Great Plains and so is really the 
Belgrade. Front Range of the Rocky Mountains. On its east 
Elevation 4,467 feet. side are the Cretaceous and Jurassic formations that 
St Pani rdw raites, Were seen above Livingston, and the crest of the 
range is made up of the massive and resistant Madi- 
son and associated limestones of Paleozoic age. On the western 
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FIGURE 17._Upturned Madison limestone and associated rocks, forming the Bridger Range, Mont., 
king north, 
slope gneiss similar to that seen on the road to Gardiner and argillite 
(hard shale) and sandstone of the Belt series are exposed, but within 
a short distance these rocks are buried beneath the soft clay and 
sand of the Tertiary lake beds. The Gallatin Valley, like that of the 
Yellowstone and also other intermountain valleys of Montana, at one 
time in the past was occupied by a lake. Into this lake were washed 
clay, sand, and gravel from the surrounding uplands and volcanic 
ash blown out from the craters of active volcanoes in the vicinity. 
The ash had the appearance of white dust, being composed of fine 
particles of glassy lava. On account of the abundance of volcanic 
ash the sediments deposited in this lake have a light color, which is 
readily recognized even at a distance of several miles. 
_ At Central iris Pi ‘aged crosses West Gallatin River and on 
€ lett 1s a beautiful rolling upland count , eve 
Central Park. acre of which is under Bi adh arid This upland 
Panation 4,324feet. 18 On the lake beds and rises toward the southwest, 
St. Paul 1,047 miles,. With the rise of the beds composing it, to a height of 
at least 500 feet above the railway. Near Manhattan 
(see sheet 16, p. 112) a branch line turns to the left (south) to 
