Marshall, R. B.  1867-1949. <br/><br/>
Results of spirit leveling in Minnesota, 1897 to 1914, inclusive / 
R.B. Marshall, chief geographer; work done in cooperation with the state of Minnesota from 1909 to 1914, inclusive; George A. Ralph, chief engineer of State Drainage Commission. 
 - Washington,  Govt. Print. Off.,  1915. 
 - 190 p. :  pl. ;  24 cm. 
 - U.S. Geological survey. Bulletin 560 .
 - United States.  Geological Survey.  Bulletin ;  560. .
<br/><br/> Includes index. 
<br/><br/><label>LCCN: </label>gs 15000377  
<br/><br/><label>Subjects--Geographic Terms: </label><br/>Minnesota--Altitudes.
<br/><br/><label>LC Class. No.: </label>QE75  / .B9 no. 560