. >> sergio perea ponce is president of tres islas. he is also a gold miner - as was his father before him. >> i traveled with him and his wife by boat to a mining camp they are building. they want to create a sustainable way to mine that can be a model for small artisanal miners. >> tres islas is located in a 1900 square mile corridor that the government has designated as the only area in madre de dios where miners can operate legally - if they qualify. the idea is to keep miners out of protected rainforest like this - and regulate how they operate. perea ponce hopes the government will legalize their operation. >> one of the ways these miners hope to qualify for legalization is by working with francisco roman to reforest areas damaged by mining. >> their job is made easier by the fact that parts of the forest are still standing. >> this lake is an example of what's possible when some forest is left intact. eight years ago - it was an active mine. now it's got life. >> there are caman around. there are giant river otters around here.