EXPLORATIONS AND SURVEYS FOR A RAILROAD ROUTE FROM THE MISSISSIPPI RIVER TO THE PACIFIC OCEAN. 
WAR DEPARTMENT. 
REPORT 
LIEUT. HENRY L. ABBOT, 
COUPS OF TOPOGRAPHICAL ENGINEERS, 
UPON 
EXPLORATIONS FOR A RAILROAD ROUTE, 
FROM 
THE SACRAMENTO VALLEY TO THE COLUMBIA RIVER, 
MADE BY 
LIEUT. R. S. WILLIAMSON, 
CORPS OF TOPOGRAPHICAL ENGINEERS, 
ASSISTED BY 
LIEUT. HENRY L. ABBOT, 
coRrs or topographical engineers. 
