“I do not invent in the least,” Thoreau insisted about his hallucinated mountain, “but state exactly what I see. I can see its general outline as plainly now in my mind as that of Wachusett” (Harding & Bode, 1974, p. 498). Thoreau’s hallucination of an enormous mountain (“in the easterly part of our town, where no high hill actually is”) recurred some twenty times over the years, and was often quite vivid; he acknowledged having ascended the mountain once or twice (Torrey & Allen, 1962, vol. 10, p. 141). An entry made in his journal two days before the hallucination and a poem about it help elucidate the mountain’s latent meaning. The hallucination, in turn, casts light on the cryptic parable or allusion: “I long ago lost a hound, a bay horse, and a turtledove”, as written in Walden. Thoreau claimed he kept the mountain to ride instead of a horse. Such rides, in the pre-Prozac era, enabled resourceful, innovative Thoreau to use the hallucination, not only for recreation, but also therapeutically.