852 J. W. Powell's Survey of the Rocky Mountain Region. 
roduced by recent orographic displacements, and he has this 
year found opportunity to study them in numerous new local- 
ities. It appears that the system of faults and flexures—the 
system of upward and downward movements— by which the 
mountain ranges and the valleys of Utah and Nevada were 
produced have continued down to the present time. Evidence: 
of recent movement has been discovered on the lines of many 
Idaho and Nevada, and demonstrating that the ancient outlet 
he had discovered the preceding summer at Red Rock Pass was 
the only one by which the lake had ever discharged its water 
to the Snake River. 
‘e Henry Mountains constitute a small grovp in South- 
eastern Utah and stand quite by themselves. They are of 
the earth, in the usual way, failed to penetrate the upper 
tc of the crust and formed subterranean lakes or chambers. 
he strata ying above the lava lakes were upbent in the form 
les, and from these bubbles of sandstone and shale 
with their cores of trap, the erosive agents of the air have 
‘ 
