264 /. P. GOODE 



States Geological Survey maps, 1 practically up to the 7900-foot 

 contour, all round the lake, and at its foot, to a point four miles 

 below the present lake outlet, at Thistle Creek Canyon, marked T. 

 C. on the map, p. 263. At this level also are found terraces, old 

 sea cliffs and beaches, and while other shore phenomena are 

 found at lower levels, as, for example, at the sixty-foot level, 

 yet in some respects the most strongly marked records are at 

 the higher level. 



Through the Thistle Creek narrows to the north, the country 

 flattens down into the Hay den Valley — a triangular depression in 

 the plateau, ten miles east and west by seven or eight miles 

 north and south. The surface of this depression is covered 

 largely with moraine deposits of glacial drift, and all round this 

 valley, particularly in the drift, the hills show a significant pro- 

 file, which, immediately below the Thistle Creek Canyon, is 

 undoubtedly terrace and sea cliff. On the upper courses of 

 Trout Creek, and across the river, east of Crater Hills, similar 

 profiles are seen. The central portion of Hayden Valley is a 

 very flat plain, extending along the two streams, Alum and Trout 

 Creeks. These two streams are wandering on 

 a very low gradient, Trout Creek showing as 

 beautiful an example of oxbows on a small 

 scale as may be found anywhere, and in its 

 wandering, its valley walls show stratified 

 clays, the fresh-cut bank in one place near 

 the roadway standing at a height of over 

 thirty feet against the stream (Fig. 2, A, B). 

 At the Grand Canyon the strongest impression one gets is 

 that the canyon is extremely young, that the river is still actively 

 corrading at bottom, and the walls all along are actively slough- 

 ing, by every process of degradation. Yet this impression of 

 youth has its greatest emphasis, only when seen from the east 

 flank of Mt. Washburne. Here, at an elevation of about two 

 thousand feet above the plateau, the whole eighteen miles of 

 canyon is in view, from the Falls to Junction Butte, dwarfed now 

 1 Yellowstone National Park Folio, U. S. Geol. Surv., Washington, 1896. 



