00670nam a2200121Ia 4500008004100000020001800041100003500059245009800094260003900192650026000231650001200491856004500503171212s9999    xx            000 0 und d  a9780874216608  aBoyer, Diane E;Webb, Robert H.  cBoyer, Diane E;Webb, Robert H.aDamming Grand CanyonbThe 1923 USGS Colorado River Expedition  bUniversity Press of Coloradoc2007  aGrand Canyon (Ariz.) -- Description and travel; Colorado River (Colo.-Mexico) -- Description and travel; Geological Survey (U.S.) -- History -- 20th century; Geological Survey (U.S.) -- Biography; River surveys -- Colorado River (Colo.-Mexico) -- History   aHistory  uwww.jstor.org/stable/10.2307/j.ctt4cgqhx