I te tau 1928, i tohua a Purcell e te Kawana C. C. Young hei Kaihanga Rori o California State. I te tau 1929, i tohua ia hei kaitohutohu hangarau mo te 1929 Hoover-Young San Francisco-Oakland Bay Bridge Commission, nana i tono te hanganga o te San Francisco-Oakland Bay Bridge. I te otinga o te mahi a te komihana, ka tohua a Purcell e te Kawana a Jim Rolph hei Kaiwhakahaere Hangarau mo te hoahoa me te hanganga o te piriti. I te wa e hanga ana, i whakamutua te kaupapa e nga mahi moana o te tau 1934
He aha? Ahakoa ēnei me ētahi atu wero, i oti te piriti i ngā marama maha i mua i te wā i whakaritea. Ko te wāhanga ki te hauauru o te piriti i whakawhirinaki ki te punga teitei o te pokapū, kei raro i te mata o te wai. Ko te tauranga nui rawa atu o te ao. I taua wā, ko te awa ki te motu o Yerba Buena te awa nui rawa o te ao. Ko tōna whakaotinga te whakatutukitanga o ngā moemoea i whakaarohia tuatahitia e ngā tāngata o te rohe i te tau 1850. I tōna otinga, koia te piriti roa rawa atu, ā, $77,600,000, te piriti tino utu nui rawa atu i hangaia. Neke atu i te 6,500 ngā kaimahi i mahi i te kaupapa.