146 GUIDEBOOK OF THE WESTEKIS' UNITED STATES. 



is cither alluvium deposited by Henrys Fork on its wide valley 



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floor or a lake deposit. It may have been laid doAvn in a lake 

 caused by the ponding of the river by a glacier in the canyon below 

 Mesa. An ice tongue or glacial dam in this canyon would have 

 held the water back in a broad lake in which would have accumulated 

 a deposit of sand and gravel such as is seen in the ballast pits. A low 

 rise indicated by a slightly greater height of the tree tops about 3 

 miles west of Island Park is said to be an old volcanic crater. Mrs. 



H. H 



e> 



At milepost 84 the railroad crosses Buffalo River, and a third of a 

 mile north of the bridge there is a small cut in rhyolite, the first expo- 

 sure of bedrock along: the track north of Island Park, This stretch 



of straight track heads nearly into the gap below Henrys Lake. On 



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the left of the gap is Sauttelle Peak, flat-topped and rising 10,123 feet 

 above sea level, or 3,800 feet above the river, Tliree miles west of it 

 is Bald Peak, The mountains east of the gap are called the Henrys 

 Lake Mountains, 



Trude is a siding for loading lumber and the station for Macks 

 Place and the fishing clubs on the river. Snow lies so deep here 



in midwinter that the residents get about on snow- 

 ^^ ^' shoes or skis and by dog teams. North of Trude 



Elevation 6,327 feet. j-hyoHte is sceu in the rock cuts. Smoothed rock 



Ogden 270 miles 



unded 



by knolls indicate that this country once was covered by a glacier. 



mileoost 90 H 



Tlie stream 



half 



prints. ^^^ reached by a wagon road that goes through a 



Elevation 6,409 feet. 

 Ogden 275 miles. 



m 



a fishing club house. Most of the water issues at two 

 places about 300 yards apart, and at each are several sprhigs. The 

 discharge of the two groups joins' midway between them and at a 

 bridge just below the junction is 120 feet wide and 3 to 4 feet deep. 

 A mile and a half north of Big Spring is a high w^ooded slope 

 trending southeastward, the front of a great flat-topped mass of lava 

 wliich came from Yellowstone Park. As the train chmbs the moun- 

 tam soon after leaving Big Springs, rhyohte is seen in the railroad 

 cuts and bowlders of black glistening obsidian or volcanic glass 

 strew the surface. These bowlders have come from ledires in the 



mountain 



milepo 



view over a timbered plateau and the alluvial flat of Henrj 



Fork, 

 visible 



material for building the station at Yellowstone. 



Hem-ys Lake, which is not 

 One of the railroad cuts near by yielded the 



