Plate 4 



1, Air view of the Gidley Quarry and vicinity, looking slightly north of cast, tlie 



foreground in Sec. 23, T. 5 N., R. 15 E. The slope in the foreground, on 

 which the quarry is visible, is on the Upper Lebo (No. 2), as is also the 

 broad valley of the Widdecombe Creek in the upper left. The higher 

 level in the upper and right parts of the picture, and along the horizon, is 

 supported by the basal Melville (Fort Union No. 3) sandstone. It is 

 typically marked by evergreen timber, but in the foreground this timber 

 extends sparsely well down onto the Lebo, Init only on talus derived from 

 the Melville. Bear Butte is dimly visible along the left part of the horizon, 

 and a small corner of Lion Butte is seen in the upper right corner. Between 

 these, small hills upheld by isolated patches of the Melville may be seen. 



2, Air view of the Gidley Quarry, a closer view, looking more to the north, of part 



of the foreground of fig. 1. The picture was taken in 1935 and shows an 

 advanced stage in the American Museum quarrying operations. The 

 approximate area covered by the LT. S. National Museum work (and since 

 filled in) is indicated by dotted lines. The larger section (A of Silberling's 

 notes) is on the far (north) side of the small coulee, and the smaller (B) 

 on the near side. The original discovery was made in the coulee near the 

 spot marked by the cross. 



