div class=trans-pagebutton class=gotoPage data-page=1Page 1button div class=trans-imageimg data-url=documentusgs-rb-21-28-33-gn-1-001-18-mils-rb-8185-13-27-150-276-mils-rb-r85-02htmlpage=1 data-page=1 class=trans-thumb lazyload alt=Page 1: USGS · rb 21 28 33 gn 1 001 18 mils rb 8185 13 27 15½0 276 mils rb r85 02 017 32 45015 106030 base from us geological survey 1966 5000 6000 1 44 e 2000 3000 4000 loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mM8Uw8AAh0BTZud3BwAAAAASUVORK5CYII= data-src=https:reader035fdocumentsfrreader035viewer20220630195fe0426bfd1bc738fe04d2e2html5thumbnails1jpg width=140 height=200 divdiv