Kate Wilhelm 
Juniper Time [EPUB ebook] 

Man reached for the stars — and failed to keep the Earth in his grasp. With the western United States devastated by drought, the survivors huddle in squalid concentration camps in the east.And still the dream won’t go away. In high orbit, an artefact is found that may be man’s first contact with aliens. The only woman who can decode it has found her future in the past, in the remote Indian territories of the Pacific Northwest. But in which direction does the planet’s survival lie?