Other Catskill essays told of fly fishing for trout, of hikes over Peekamoose Mountain and Mill Brook Ridge, and of rafting down the East Branch of the Delaware River. It is for these that he is still celebrated in the region today, and chiefly known, although he traveled extensively and wrote about other regions and countries, as well as commenting on natural-science controversies of the day such as the theory of natural selection. He entertained philosophical and literary questions, and wrote another book about Whitman in 1896, four years after the poet's death.