Nelson, Willis H.  1920-2010 <br/><br/>
Geology of the Duck creek pass Quadrangle Montana / 
by Willis H. Nelson. 
 -- Washington :   United States Government Printing Office,   1963 
 - 56 p. + map. -- 
 (Geological Survey Bulletin  ;  1121-J).
<br/><br/><label>Subjects--Topical Terms: </label><br/>Geología<br/>Montana
<br/><br/><label>Universal Decimal Class. No.: </label>55(786)