GEORGE DAVIS LOUDERBACK 



the Roseburg somewhat inland and in the latitude of the Coos Bay 

 area. Of the Riddles quadrangle which adjoins the Roseburg on 

 the south, and corresponds in latitude to the Port Orford, only a 

 topographic sheet has been issued. It will be noted that these two 



Index Map of Southwestern Oregon 

 The areas of the Geological Survey quadrangles are inclosed in heavy broken lines. 



pairs of quadrangles are separated by a strip, one quadrangle in 

 width. This unmapped area represents what is known as the Oregon 

 Coast Range which runs north and south, and is broad enough to 

 occupy the unmapped strip and extend its foothills a short distance 

 into the Roseburg area on the east, and into the Coos Bay and Port 



