262 Annals of the Carnegie Museum. 



border of a precipice, and, through openings between poplar groves, 

 beheld one of the most picturesque sights I had ever seen. Down deep 

 beneath me lay a narrow sheet of water (Plate XVII), winding in and 

 out narrowing and expanding between abrupt walls and steep talus 

 slopes on one side and steep wooded cliffs on the other. South of where 

 I stood, near the broadest portion o^" the lake and nearer to the western 

 shore, stood ahigh conical mound (Pyramid Island). A little farther 

 south a high promontory projected into the lake, and a little farther 

 south was another headland as the lake divides into three long narrow 

 inlets which are confined between precipitous walls. The most eastern 

 of these inlets is the one, the head of which I had previously seen. 



The water is very deep except on the borders and in the narrowest 

 portions of the lake. Here Chara and other water-plants grow from a 

 white mud or ooze, which forms a terrace around the borders of the lake 

 and covers the bottom of the shallower portions. I supposed this white 

 ooze to be lime left by the decaying Chara. Undoubtedly this, to- 

 gether with dust and water-borne sediments, are very slowly filling the 

 lake. Much of the Tertiary sediments of the west were supposed to 

 have been deposited in lakes, and it would be extremely interesting if 

 some one would study the principal types of lakes, ascertain the char- 

 acter of the deposits, and discover how they are actually made. This 

 lake, and others of the same character near it, would furnish studies of 

 the most unique and fascinating interest. On account of its having 

 been so long isolated. Cliff Lake contains, it is said, fish and other 

 forms of life different from any others in this region. Their study 

 would undoubtedly throw much light on the progress and distribution 

 of life. 



Above and below are other lakes in the same gorge, which appears 

 to be the canon of an ancient stream that flowed between the Centen- 

 nial and Madison valleys. At the lower end of the lake the canon is 

 filled with debris which dams the water. The surrounding country is 

 picturesque and full of scientific interest. It ought to be a paradise 

 for artists, geologists, and sight-seers, and yet, though many pass 

 within a few miles of it to " see the sights " in the Yellowstone Park, 

 comparatively few ever gaze on its hidden, though unique, grandeur 

 and beauty. So far as natural scenery is concerned I know of nothing 

 in the National Park which approaches it. 



Near the foot of the mountains on the east side of Reynold's or 

 Madison Pass, is what at a distance appears to be a fault. It looks as 



