36 



GEOLOGIC GUIDEBOOK ALONG HIGHWAY 49 



[Bull. 141 



FIG. 1. Map of the northern Sierra Nevada showing the highways, in black ; the topographic quadrangles which were used in compilation of the accompanying strip 

 maps, in brown ; the position of each strip map section in relation to these quadrangles, in red ; and, as shown in the map index, the sources of geologic data used in making 



the strip maps. 



