The Line 3 project has gotten approval from Minnesota regulators. But the fight over this oil pipeline is far from over.

In the early 2000s, the Keystone XL oil pipeline became one of the most powerful symbols in the fight against climate change. And since then, it's not just local landowners fighting pipelines in their backyards anymore. It's environmental groups, Native Americans tribes, farmers and ranchers, and a crucial addition to the alliance -- climate change activists. But how did it begin?

Pipelines have become a potent issue for Native American and indigenous people, who are fighting them across North America. Part of the fight is over culture and identity. But it also involves a messy history of land and treaties, and a long, complicated relationship with the U.S. government.

This story isn't just about the risks of transporting huge amounts of oil through pipelines. It's also about the reward that oil provides.

Pipelines are everywhere: 2.5 million miles of them form a web under our feet, our rivers and our roads. They're at the forefront of an epic tug of war between our reliance on oil and the risk that oil poses to the future of our world.

All over the country, people are moving to camps in the woods, climbing trees, chaining themselves to bulldozers, all in the name of stopping an oil pipeline. What's going on? Why is there suddenly a dramatic conflict around pipelines? And is it really even about pipelines at all?