38o /. T. PARDEE 



that in the slopes above are wanting. These pebbles range in size 

 up to four or five inches in diameter and, together with larger masses 

 of quartzite associated with them and possessing rounded edges, are 

 undoubtedly waterworn. Among them no pebbles of a material 

 differing from the quartzite bed rock of the immediate vicinity are 

 found. This "trail" can be easily followed around the north slopes 

 of the buttes, tracing a deep re-entrant angle as it curves around the 

 head of the ravine leading north from the saddle. Here the pebbly 

 deposit gives place to a more extensive one of fine, slightly yellowish, 

 quartz sand, that in one place has been channeled by a rain gully to a 

 depth of eight or ten feet. 



Below the 4,200-foot contour the slopes exhibit a succession of 

 parallel trails, exact counterparts apparently of those of Mount Jumbo, 

 except that many of them are conspicuously marked by rows of trees 

 and shrubs. One at 3,700 feet elevation is more than ordinarily 

 prominent. It might at one place be easily mistaken for an abandoned 

 wagon-road along which a row of trees had been set. Its cross-section 

 is similar to that of the one at 4,200 feet, but of larger proportions, 

 the "road bed" twelve to fifteen feet wide being likewise formed of 

 a deeper soil than is found upon the adjacent slopes, containing water- 

 worn pebbles and quartzite fragments. 



Just below this contour the quartzite disappears beneath the 

 incoherent sediments of the "bench lands" upon which the series of 

 "trails" still continue to be faintly exhibited down nearly to the 

 river's flood plain. 



Douglass^ describes these benches as beds of sand, gravel, and 

 volcanic ash of Miocene age in part. Remnants of the "trails" are 

 not only preserved upon open slopes of this easily eroded material, 

 but upon the sides of the ravines that dissect it, showing that time 

 since the "trails" were formed has been too brief for any material 

 alteration of the topography by erosion. 



On the northern slope of the first butte at about 4,100 feet eleva- 

 tion a large subangular bowlder of gneissoid granite rests upon the 

 surface. It has a volume of perhaps five cubic yards. Several similar 

 bowlders have been noted in the neighboring basin of Three-Mile 



I Earl Douglass, "A Geological Reconnaissance in North Dakota, Montana, 

 and Idaho, etc.," Carnegie Mus. Annals, V (1909), 264, 265. 



I 



