 Surrounding the base of the monument is a terrazzo floor embedded with a " star map " . The map depicts the Northern Hemisphere sky at the moment of President Roosevelt 's dedication of the dam . This is intended to help future astronomers , if necessary , calculate the exact date of dedication . The 30 @-@ foot @-@ high ( 9 @.@ 1 m ) bronze figures , dubbed " Winged Figures of the Republic " , were each formed in a continuous pour . To put such large bronzes into place without marring the highly polished bronze surface , they were placed on ice and guided into position as the ice melted . Hansen 's bas @-@ relief on the Nevada elevator tower depicts the benefits of the dam : flood control , navigation , irrigation , water storage , and power . The bas @-@ relief on the Arizona elevator depicts , in his words , " the visages of those Indian tribes who have inhabited mountains and plains from ages distant . " 
 Surrounding the base of the monument <a href='drop_aux' title='1'><mark>is</mark></a>a terrazzo floor embedded with a " star map " . The map <a href='uninflect' title='2'><mark>depicts</mark></a> the Northern Hemisphere sky at the moment of President Roosevelt <a href='null_genetive' title='3'><mark>'s</mark></a>dedication of the dam . This is intended to help future astronomers , if necessary , calculate the exact date of dedication . The 30 @-@ foot @-@ high ( 9 @.@ 1 m ) bronze figures , dubbed " Winged Figures of the Republic " , <a href='uninflect' title='4'><mark>were</mark></a> each formed in a continuous pour . To put such large bronzes into place without marring the highly polished bronze surface , they <a href='uninflect' title='5'><mark>were</mark></a> placed on ice and guided into position as the ice melted . Hansen <a href='null_genetive' title='6'><mark>'s</mark></a>bas @-@ relief on the Nevada elevator tower <a href='uninflect' title='7'><mark>depicts</mark></a> the benefits of the dam : flood control , navigation , irrigation , water storage , and power . The bas @-@ relief on the Arizona elevator depicts , in his words , " the visages of those Indian tribes <a href='null_relcl' title='8'><mark>who</mark></a><a href='been_done' title='9'><mark>have</mark></a> inhabited mountains and plains from ages distant . " 
Surrounding da base of the monument a terrazzo floor embedded with a " star map " . The map depict the Northern Hemisphere sky at tdamoment of President Roosevelt  dedication of the dam . This is intended to help future astronomers , if necessary , calculate thdaxact date of dedication . Theda @-@ foot @-@ high ( 9 @.@ 1 m ) bronze figures , dubbed " Winged Figures of the daublic " , was each formed in a continuous pour . To put such large bronzes into place without marring the hdaly polished bronze surface , they was placed on ice and guided into position as the icdaelted . Hansen  bas @-@ relief on the Nevada elevator tower depict the bendats of the dam dalood control , navigation , irrigation , water storage , and power . The bas @-@ relief on the Arizona elevator depicts , in his words , " the visagdaof those Indian tribes done inhabited mountains and plains from ages distant . "