A Week on the Concord and Merrimack Rivers, like Walden, mixes observations of natural phenomena with discussions of their symbolic significance. The Maine Woods and Cape Cod read more like pure travel literature. In these last two books Thoreau encountered forms of nature not easily reconcilable to his faith in an external world friendly to man. In Cape Cod he describes the purely destructive force of a storm at sea. In The Maine Woods he writes of climbing Mt. Katahdin, New England’s second highest peak; he reaches the summit, possibly only the sixth person ever to do so, and is shocked by what he finds there: a grey, barren expanse, strewn with rocks and totally indifferent to human existence. Thoreau’s confidence in a benign nature did not outwardly change, but a reading of his Journals reveals that he sometimes continued an adherence in his published books to ideas that he had privately abandoned.