At the time, he did not know Yin. He emailed several foundations in the US, telling them about her efforts in the Chinese desert. The campaign eventually helped secure a $5,000 donation.

　　Sakolsky later put the amount into perspective. Yin"s annual income at the time was roughly the equivalent of $250. The donation was worth about 20 years of her savings.

　　The following spring, accompanied by Bai Fan, then vice principal of Luoyang Foreign Language School, Sakolsky traveled deep into the Maowusu Desert for the first time.

　　Bai still remembers the details. The seedlings were no thicker than a finger. Water had to be carried from far away. Yin watered the trees one scoop at a time.

　　Faced with the barren landscape, Sakolsky repeatedly said that it seemed "impossible."

　　"He found it difficult to imagine that trees could really grow in a place like this," Bai said.

　　Yin remembers the failures, too. She married into the Maowusu Desert from Northwest China"s Shaanxi Province at 19. In those days, sandstorms could bury the entrance to a house overnight. She vowed that she would rather work herself to death planting trees than allow the sand to destroy her life.

　　In 1986, she sold a sheep to buy 600 saplings and planted them around her home. After a major windstorm, fewer than 10 survived.

　　But she did not stop. "If 10 out of 600 can survive, that means trees can grow here," she recalled thinking.

　　She gradually learned which species could withstand drought, where water was likely to collect and how to keep seedlings from being blown away. "There was no shortcut," she said. "You fail, then try again. If something works, you keep doing it. And you do it year after year."