| The valley is one of the westernmost depressions in
the desert between the Sierra Nevada and the Rocky Mountains. Its floor, a
thousand feet above sea level is a wide, white, alkaline expanse - an ancient
lake bed strewn with greasewood and volcanic debris, ascending into alluvial
fans that resemble enormous earthen glaciers. From a distance, the mountain
canyons are deep wrinkles in a naked torso, concealing fecund microenvironments
of desert willows, columbines, and maidenhair ferns-the products of astounding
year-round streams that stay cool even when the air temperature reaches 120
degrees. Where these streams merge with the valley floor they form a salt
marsh, which is a haven for invertebrates and migrating birds. North of the
marsh are sand dunes, the beach at the edge of the |
