ðə mˈæpɪŋ ɪnvˈɑːlvd sɚvˈeɪɚz dɹˈɔːɪŋ bˈeɪs mˈæps æt skˈeɪlz ʌv sˈɪks ˈɪntʃᵻz tə ðə mˈaɪl, jˈuːzɪŋ wʌt wʌz ðˈɛn ðə mˈoʊst ˌʌp tə dˈeɪt dʒˌɪəɡɹˈæfɪkəl tɛknˈiːks ɹˈeɪdɪˌoʊ tˈaɪm sˈɪɡnəlz ænd sˈɛkstənts tʊ əbzˈɜːv stˈɑːɹz ænd dʒɪˈɑːlədʒˌɪsts, ɪŋklˈuːdɪŋ kˈɛɹi, plˈɑːɾɪŋ ðə dʒɪˈɑːlədʒi ˌɑːntʊ ðə mˈæps fɹʌm ɛkspˈoʊʒɚz ɪnðə bˈæŋks ʌv stɹˈiːmz.
The mapping involved surveyors drawing base maps at scales of six inches to the mile, using what was then the most up to date geographical techniques (radio time signals and sextants to observe stars) and geologists, including Carey, plotting the geology onto the maps from exposures in the banks of streams.