96 YEARBOOK, PUBLIC MUSEUM, MILWAUKEE [Vol. II. 



torrent as huge boulders and becomes very curiously polished and 

 eroded by this action. In spite of the many rapids and stretches of 

 swift water, there are no cataracts or waterfalls of any kind in the 

 course of the stream. Light boats have, on two or more occasions, 

 made the trip through from Green River, Wyoming, to Needles, Cali- 

 fornia, traversing all the canyons of the Colorado, and no obstructions 

 preventing this sort of navigation were encountered, though the journey 

 is in many places a very perilous one. 



At first one can scarcely realize that this enormous excavation was 

 accomplished by the work of a river and its tributary streams. Many 

 are inclined to believe that an enormous earthquake or some other al- 

 most occult activity has here opened up a crack in the surface of the 

 ground through which the river afterwards found its way. Such, how- 

 ever, is not the case, as the rocks on both sides of the canyon wall are 

 identical in position and thickness, and in their order one above another, 

 showing that no serious displacement of the once continuous rock strata 

 has ever occurred. 



The selection of a suitable site for a group to picture this enormous 

 example of erosion was extremely difficult, for the panorama from al- 

 most any point upon the rim of the canyon was so exceptional as to be 

 worthy of consideration. Besides, the views from farther down within 

 the walls of the canyon were also interesting and in many ways unique. 

 In order to be sure that the most exceptional of all might be chosen, it 

 was necessary for the party to travel as far as possible along the south 

 rim of the canyon and, also, to visit the lower levels and the Tonto Plat- 

 form, thereby gaining a more intimate knowledge of the canyon as a 

 whole. 



It was decided at first to travel to the lower levels of the canyon 

 and to decide once for all between the view from the rim and that from 

 the lower platform. To do this we traveled along the rim road west- 

 ward from the hotel about eight miles, to the head of Hermit Trail, 

 one of those trails descending to the river from the south rim of the 

 canyon. This trail has long been in use by the Indians in descending 

 to a spring about a thousand feet below the rim of the canyon; but the 

 lower part was built especially for the use of tourists. In descending 

 the canyon, the hard rocks which have resisted erosion form the chief 

 obstacles to the building of a trail. These are, principally, an upper 

 white sandstone and a lower reddish limestone. These two formations 

 tend to weather into vertical walls, and it is only very rarely that one 

 is able to cross them. The other rocks forming the walls of the canyon, 



