00817nam a22002051  4500001001300000003000400013005001700017008004100034010002200075040003700097043001200134050001600146100003100162245014100193260007800334300006100412490005600473650002300529830005900552gs 17000080 DLC20260227111320.0880107s1916    iluab        s00010 eng c  ags 17000080 //r88  aU.S. Geol. Survey Libr./ICUcICU  an-us-il0 aQE105b.A1610aSauer, Carl Ortwin,d1889-10aGeography of the upper Illinois Valley and history of development,cby Carl Ortwin Sauer. Printed by authority of the state of Illinois.0 aUrbana,bIllinois state geological survey, University of Illinois,c1916.  a208 p.bfold. front., illus., fold. map, diagrs.c26 cm.1 aIllinois. State geological survey. Bulletinvno. 27 0aGeologyzIllinois. 0aBulletin (Illinois State Geological Survey) ;vno. 27.