40 THE AMERICAN BOTANIST 



more extended description of the stations visited be given for 

 the benefit of others who may chance to pass that way. 



NoNNEzosHE Arch 



One of the principal objectives of our expedition was a 

 visit to the great natural bridge, known as Nonnezoshe Arch 

 or Rainbow Bridge, just over the line in Southern Utah. This 

 was discovered by the leader of our party. Prof. Byron Cum- 

 mings, in 1909, and has since been visited by a limited number 

 of explorers, ranchmen, globe-trotters, and naturalists. The 

 bridge is a vast arch of stone, the largest in the world, span- 

 ning Bridge Creek Canyon not far from its junction with the 

 Grand Canyon of the Colorado. It is 274 feet wide and more 

 than twice as high as Niagara Falls. As may be seen from 

 our illustration, the bridge and the walls of the canyon in 

 which it is located are practically bare of vegetation and offer 

 poor collecting ground for the botanist. The only plants 

 collected here were Petrophyton caespitosuni, which formed 

 mat-like growths depending from the rock shelves, and Adian- 

 tum Capillus-Veneris which was common on dripping ledges 

 in the shadow of the bridge. The canyon, which heads to- 

 ward Navajo mountain, contains considerable water and in its 

 upper reaches supports a growth of cottonwoods, willows, 

 and the like, none of which were collected. By means of a 

 sixty-foot rope our party descended from an adjacent cliff 

 to the top of the bridge, the women being second of their 

 sex to accomplish this feat. 



Navajo Mountain 



Barring the only direct route to the bridge, Navajo moun- 

 tain rises to a height of 10,416 feet. Its slopes afford almost 

 the only source of water in an extensive region, and it is 

 naturally the stopping place for all sorts of caravans. There 

 arc few spots in the United States more inaccessible. On the 



