Gilbert's Geology of the Henry Mountains. 21 
ortion, the remains of three laccoliths: to the left the ‘“‘Geikie” 
accolith ; along the middle portion (S) the ‘‘ Shoulder” lacco- 
lith, overlapping the base of the Geikie; and to the right (N) 
two miles to the south of the Geikie, is the ‘‘ Newberry arch,” 
the last making a knob 1700 feet high, standing by itself. 
In the rear is the pyramidal Ellen Peak; to the left of it, in the 
> 
distance, is the “Marvine” laccolith; and, to the right, still 
Part of Mount Ellen from the west; highest point 11,250 feet. 
another, named the F laccolith. Lewis’s Creek cuts across a 
flank of the Newberry arch and ‘exposes a portion of the 
[trachytic] nucleus,” overlaid by 100 to 200 feet of shale, and 
this by the Henry’s Fork conglomerate. Erosio 
a on two sides the interior trachyte of the Geikie lacco- 
. 
and the contact face of the trachyte is bare.” The extreme 
