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EXPLORATIONS AND SURVEYS FOR A RAILROAD ROUTE FROM THE MISSISSIPPI RIVER TO THE PACIFIC OCIOAN. 
WAR DEPARTMENT. 
ROUTES IN CALIFORNIA AND OREGON EXPLORED BY LIEUT. R. S WILLIAMSON, CORPS OF TOPOGRAPHICAL 
ENGINEERS, AND LIEUT. HENRY L. ABBOT, CORPS OF TOPOGRAPHICAL ENGINEERS, IN 1855. 
BOTANICAL REPORT. 
WASHINGTON, D. C. 
1 8 5 7. 
