Book excerpt: It is a high valley edged by serrated peaks, a remote expanse the size of Connecticut lying, as if forgotten, between two mountain ranges. Here, North AmericaÕs tallest sand dunes blow against glacier-gouged summits, the Rio Grande begins its long journey from snowflake to saltwater, and vast reaches of desert scrub hide verdant pocket wetlands. ColoradoÕs San Luis Valley is not a place for the timid. Sizzling hot in summer, frigid cold in winter, this huge landscape is humbling in its openness, a place defined by the rhythms of natureÑand by the thrust and parry of male courting female in the ritual dance of sandhill cranes. These majestic birds arrive by the thousands twice a year to feed, rest, and socialize in the valleyÕs wetlandsÑinvisible except from the airÑand their cries temper the constant wind. Susan Tweit lives in the high desert of southern Colorado not far from the valleyÕs dunes and wetlands. With the precision of a scientist and the passion of a poet, she guides readers through this land of sand dunes and sandhill cranes, describing its natural features and tracing its human history from buffalo hunters and conquistadors to Hispanic farming communities and UFO observatories. And in stunning images, photographer Glenn Oakley brings his intimate feel for light and landscape to portraying not only the subtle beauty of this high-desert sanctuary but also the grandeur of the cranes in flight. As an intimate look at Great Sand Dunes National Park and Preserve and the San Luis Valley, this book reveals a desert place as seductive and sobering as existence itself.