Novel by Su Wei.

The Invisible Valley (lit. Mi Gu, "Vale of Enchantment") is the tale of a spunky, nonconformist "sent-down youth" (one of the millions of middle- and high-school age students exiled to the countryside to "re-educated" after the Cultural Revolution) who discovers a hidden utopia, an isolated community of migrants living deep in the jungles of Hainan Island. When their matriarch Jade takes him as lover, he must play a precarious balancing game between two worlds: the haunted society of the "driftfolk," and the twisted irrationalities of Mao’s China. (copied from http://www.austinwoerner.com/suwei.html)