Growing conflicts over development in South America have come to a head in Bolivia, where indigenous groups are resisting a highway project that would slice through a national park. How Bolivia resolves this showdown could point the way for other regions seeking to balance economic growth and the environment.

Carmelo Aguilera steadies the dugout canoe as his 11-year-old son, Juan Gabriel, stands precariously and aims his bow and arrow toward the Secure River below. “Fish flesh makes better bait,” says the boy, explaining why the dawn expedition begins with a hunter’s weapon rather than a hook and line.

Deep inside Bolivia’s Isiboro Sécure National Park and Indigenous Territory, known as TIPNIS, the Aguileras live more than 30 hours by boat from the nearest city, surviving mainly on fish and a few homegrown crops. “The river is our lifeblood,” says Aguilera, 62.