Black Sun by Edward Abbey

Now in a Harper Perennial Modern Classics edition, the timeless novel that chronicles a reckless romance in the wilderness, from Edward Abbey, one of America's foremost defenders of the natural environment.
Black Sun is a bittersweet love story involving an iconoclastic forest ranger and a freckle-faced "American princess" half his age. Like Lady Chatterley's lover, he initiates her into the rites of sex and the stark, secret harmonies of his wilderness kingdom. She, in turn, awakens in him the pleasure of love. Then she mysteriously disappears, plunging him into desolation.
Black Sun is a singular novel in Abbey's repertoire, a romantic story of a solitary man's passion for the outdoors and for a woman who is his wilderness muse.
"Like most honest novels, Black Sun is partly autobiographical, mostly invention, and entirely true. The voice that speaks in this book is the passionate voice of the forest," Abbey writes, "the madness of desire, and the joy of love, and the anguish of final loss."