BULLETIN 612 



SHEET No. 23 



GEOLOGIC AND TOPOGRAPHIC MAP 



OF THE 



OVERLAND ROUTE 



From Omaha. Nebraska, to San Fi 



California 



Base compiled from United States Geological Survey Atlas Sheets, 

 from railroad aligrinients and profiles supplied hy the Union Pacific 

 Railroad Company and the Southern Pacific Conapany and from addi- 

 tional Information collected with the assistance of these conapanies 



UNITED STATES GEOLOGICAL SUHVEl 



GEOTIG-E OTIS SMITH, DIRECTOR 



David White, Chief Geologist 



R, B. Marshall, Chief Geograx>her 



1915 



Each quadrangle shcum on the map with a name in pa^entkesis in the 

 lower left comer is mapped in detail on the U. 5. G, S. Topographic 

 sheet of that name. 



I L 



o 



3 



-L. 



4 



_L 



5 M'tles 



FIGURE !7,-5KETCH MAPS SHOWING CAPTUP^E: OF UPPER PART OP BEAR RIV^R BY SOUTH 



FORK OF YUBA RIVER 

 TO IDENTIFY LOCATIO^ 



CA.PTJRE; ^, AFTER CAPTURE. nAILROAD SHOWN 



EXPLANATION 



A Modem stream deposits (alluvium) 



B Glacial deposits (moraines) ; Pleistocene 



Lavas (chiefly andesite but includinc: rhyolite, basalt 

 etc.), flows, tuffs, or tuff" breccias (shown by stippled 



pattern): Neocene 



D Auriferous Cgold-bearing) gravels : Neocene 



E Clays, sand, and gravel, with some coal beds (lone for- 

 mation) ; Eocene 



Granite (chiefly gn^nodiorite but includmg granite por- 

 phyry. gabbro» peridotites, serpentine, etc.); late 

 Jurassic or early Cretaceous 



Slates, sandstone, and conglomerate (Mariposa slate), 

 Jurassic ; calcareous slates and limestones (Sailor Can- 

 yon formation), Triassic Locally changed to schist 

 and other metamorphic rocks 



ELEVATIONS IN FEET ABOVE MEAN SEA LEVEL 



The distances f^-cr^' Omaha, Nebraska^ an shown every 10 miles 

 The cfvssties on the railroads art spaced I mUe apart 



Sheet A/o 



25*30 



