He was a member of the United States Geological Survey during the explorations of Yellowstone National Park, from 1871 to 1875.
hiː wʌzɐ mˈɛmbɚɹ ʌvðə juːnˈaɪɾᵻd stˈeɪts dʒˌɪəlˈɑːdʒɪkəl sˈɜːveɪ dˈʊɹɹɪŋ ðɪ ɛksploːɹˈeɪʃənz ʌv jˈɛloʊstˌoʊn nˈæʃənəl pˈɑːɹk, fɹʌm wˈʌn θˈaʊzənd ˈeɪthˈʌndɹɪd sˈɛvənti wˈʌn tə wˈʌn θˈaʊzənd ˈeɪthˈʌndɹɪd sˈɛvənti fˈaɪv.