This historic image taken at Yarinacocha, Peru near the Ucayali River in 1966 by photographer and explorer Chuck Clark captures an important moment in the history of the Amazon Rainforest.  During the 1960s, American missionaries were quite active in the Amazon jungle making contact with indigenous Amazonians who were previously uncontacted tribes and living voluntary isolation from Western society.  In this photo, a missionary wife and the children of missionaries are waving goodbye to Americans Hattie Kneeland and Harriet Fields who were leaving on their historic mission to make the first peaceful contact with the fierce Matsés Indians who were in a de facto state of war with both Peruvians and Brazilians.  Hattie and Harriet spent two years preparing for this mission by learning the Matsés language from a Peruvian woman (Sophia) who had been captured by the Matsés tribe and later managed to escape.  Their mission was successful, and they helped the Matsés Indians make peace with the Peruvians and Brazilians and adapt to the modern world.  In addition, they set up a model bilingual education program so that the Matsés could preserve their language for future generations to come.