U. S. GEOLOGICAL SURVEY 



BULLETIN 707 PLATE XLI 



A. GOLD DREDGING. 



Great dredges like those used in deepening harbors and in excavating the Panama Canal are 

 set to work in the heart of the Rocky Mountains, digging up and washing gravel for the gold 

 it contains. This view shows the great heap of washed gravel that is left in the wake of the 

 dredge. Photograph by F. L. Ransome. 



B. RAINBOW HIGHWAY. 



Automobiles now traverse the grand canyon of the Arkansas as readily as railroad trains, owing 

 to the recent completion of the Rainbow Highway from Parkdale to LeadviUe. In many 

 places the cost of construction was as great as that of the railroad ou the opposite banK. 

 Photograph by the U. S. Forest Service. 



