Long ago, in the hot, moist folds of the Amazon, a people walked and walked to keep the sun from setting. According to Peruvian writer Mario Vargas Llosa, the Machiguenga believed if they ever stopped walking, the sun would fall from the sky. Then the missionaries came with new beliefs. Soon after, settlers arrived from the coast and the highlands. And now another wave, this time of businessmen who tell of a new kind of sun, below the ground, waiting to be transformed into light and money.

For a consortium of seven energy companies, including Hunt Oil of Texas, the vast natural gas deposit at Camisea represents potentially large profits through exports to the U.S., where demand is rising, and the conversion of vehicles and factories in Peru to natural gas. Officials in Peru say the Camisea field, one of the largest in the Americas, could mean energy independence for the nation. For the 10,000 Machiguenga navigating their way along the “River of the Moon,” the Camisea gas project means change, and the unknown.

Environmentalists and human rights organizations warn of irreparable damage to the Amazon and its people if the project moves forward as planned. They cite previous petroleum projects in Peru and Ecuador as reason to proceed with extreme caution, if at all, in Camisea. The energy companies respond that they have learned from the mistakes of the past, and that Camisea can be a model of how to do things right. It’s a debate that could affect the future of rainforest oil development around the world. And the Machiguenga are caught in the middle.