122 BULLETIN UNIVERSITY OF MONTANA 
The snow mass behind the spur to the left in Plate XXXV. flows into a 
small and beautiful lake, Leash lake. This lake is said by those wha 
have seen it to be of surpassing beauty, usually full of snow, and visible 
only when almost upon it, so well is it hidden in the cliffs. The water 
entering the lake flows down the side of McDonald northward. After 
leaving Leash lake the water flows west, coming down and joining the 
stream from Teton on the north and the stream from the west glacier of 
McDonald. 
Post creek, the outlet of McDonald lake, on the 30th of June, 1900, 
carried 473 second feet of water. The place at which the water was 
measured was some miles down creek from the lake, at a lower elevation 
than the lake by a thousand feet, and with considerable loss between place 
of measurement and lake through irrigation. 
