Walk away quietly in any direction and taste the freedom of the mountaineer. Camp out among the grass and gentians of glacier meadows, in craggy garden nooks full of Nature's darlings. Climb the mountains and get their good tidings. Nature's peace will flow into you as sunshine flows into trees. The winds will blow their own freshness into you, and the storms their energy, while cares will drop off like autumn leaves. As age comes on, one source of enjoyment after another is closed, but Nature's sources never fail. … The petty discomforts that beset the awkward guest, the unskilled camper, are quickly forgotten, while all that is precious remains. Fears vanish as soon as one is fairly free in the wilderness.

"The Yellowstone National Park", The Atlantic Monthly, volume LXXXI, number 486 (April 1898) pages 509-522 (at pages 515-516); modified slightly and reprinted in Our National Parks (1901), chapter 2: The Yellowstone National Park - 'Our National Parks (1901)