Painted Valley was home to a community of chimpanzees some distance from Ape City, cut off from the outside world by a high mountain pass which ran by Mount Lam. In the distant past the chimps of Painted Valley had overthrown their orangutan and gorilla overlords and thrown them into a pit inside a cave. Forty years before Taylor came to earth, an earthquake caused the river that flowed through Painted Valley to become contaminated by the Forbidden Zone, and in subsequent years a number of chimps had become mutated as a result. These mutants were banished to the caves, where they were fed by the community and projected mental images of monstrous creatures to scare away unwanted visitors. When Vitus, Milo and Cornelius visited Painted Valley in search of supplies they were initially welcome