DENVER & RIO GRANDE WESTERN ROUTE. 131 



The traveler has now seen the lava flow, though he has probably 

 not seen the vent or volcano from which it must have come, but if 

 he scans closely the hills across the valley he will see that some of 

 them are littered with fragments of the same dark rock that com- 

 poses the flow and that others consist wholly of that rock. The 

 volcano must have been near the top of the first series of hills, as 

 shown in Plate LYI, B^ but its crater is now obscured by the lava 

 that consolidated in its throat. The vent was small, but it has all 

 the essential features of a true volcano. The ravine down which 

 the fiery flood rolled into the valley, leaving some of the melted 

 rock adhering to its sides as it passed, may be seen from the train. 

 (SeePl. LVI,^.) 



This eruption seems to have been the last expiring gasp of forces 

 that long before poured out immense floods of molten material in 

 this region. The material erupted at this place was only enough 

 to fill the valley to a depth of 50 or 60 feet but not enough to turn 

 the river from its course. The lava extends down the valley half a 

 mile beyond milepost 341. 



As the train rounds the bend, just below the limit of the lava flow, 

 the valley of Colorado Eiver is visible on the north (right), and 

 Eagle River unites with this stream a few hundred yards farther 

 on, but the junction is not near enough to be seen from the train. 

 Colorado Eiver has its source on the east slope of Mount Eichthofen, 

 in the northern part of Middle Park, and those who went to the 

 summit of the mountains (Corona) on the "Moffat road" could 

 look down on this west side into some of the head tributaries of 

 this river. After flowing westward across Middle Park the river 

 escapes from that natural basin in the mountains by Gore Canyon, 

 a rugged gorge which it has cut through the Park Eange — the same 

 range which the traveler saw on the east (right) at Tennessee Pass. 

 Gore Canyon is cut in granite, but below the Park Eange the valley 

 is much like that of Eagle Eiver, consisting of a succession of nar- 

 row canyons with stretches of broad vallej^ between. This alterna- 

 tion is repeated man}^ times along the river before it is joined by 

 Eagle Eiver at the siding of Dotsero. At the point of junction there 

 is visible far to the north a high plateau, which is locally called The 

 Flattops or the "White Eiver Plateau, from the stream that drains 

 its western slope. It has an altitude of 11,000 to 12,000 feet and is 

 noted as the greatest hunting ground of western Colorado. It was 

 here that Theodore Eoosevelt made one of his famous hunting trips 

 while he was President of the United States. The preservation of 

 the plateau at this high altitude is largely due to the fact that soon 

 after its even surface was formed it was covered from some vent in 

 this region with lava, which afterward cooled and consolidated into 

 a basalt that has successfully withstood the action of the elements 



