The Earth Is All That Lasts

From the back cover of the Del Rey first edition: "The Homecoming - The People considered Coconino the most favored son of the Mother Earth. To Phoenix, a teacher from the technological enclave of the Mountain, he was little more than a brash savage. When, together, they found and befriended the legendary alien antelope known as Tala, Phoenix thought it a sign that she had been accepted by the Mother Earth and the People and left her bitter part behind. But she soon learned that Mother Earth demanded a high price for her gifts. For after 500 years of silence, Mankind was returning to its abandoned homeworld searching for signs of life. To Coconino, the words of the Mother were clear - Mankind must never again be allowed to despoil the planet. But Phoenix face a more difficult choice - between the People she had come to love and honor and the promise of off-world technology that could make her life whole once again..."